Little is known of Thomas's family but he does tell Sarah O'Brien and later Jimmy Kent that his father was a clockmaker. As a result, he apparently has a natural affinity with clocks, saying that he grew up with them and "understands" them. O'Brien calls him the house's clock expert. He has worked in Downton for over 10 years and as a footman used to wind all the clocks in the house. He also appears to be quite talented at cricket, Lord Grantham stating as much, noting he got most of the house team's runs in the 1919 match. He mentions to Bates having a cousin in Bombay. He is gay, and once had an affair with the Duke of Crowborough, while the Crawleys were in London. In 1922, he brought his acquaintance Phyllis Baxter into the house to serve as a lady's maid to Lady Grantham. It is only in 1924 that it is revealed that Baxter was a friend of his sister's when they were growing up. This is also the first mention of Thomas having a sister, thereby shedding some more light on his background. When Thomas lies about his father's illness in order to go to London to receive the gay aversion treatment, Baxter tells him she feels sorry, as his father was always nice to her. Thomas replies bitterly that he was never very kind to him, implying a difficult relationship with his father.<tabber>|-|Series 1=
At the beginning of the series, Thomas the footman has been working toward being a valet, and the position of valet to Lord Grantham looks like it will be his, when suddenly Lord Grantham hires John Bates who has not been a valet before and walks with a cane. Thomas and Sarah O'Brien, Thomas's friend and Lady Grantham's lady's maid, begin plotting to get John Bates fired, and they try to sabotage his work.
Thomas with the Duke.
The Duke of Crowborough has come to Downton, ostensibly to pay his condolences for the deaths of James and Patrick Crawley on the Titanic. In actuality, Thomas has written to the Duke to advise him that Robert Crawley will contest the entailment, and Mary Crawley will be a wealthy heiress. The Duke wants a wealthy wife (to aid his financial discomforts) and Thomas wants to be hired as his personal valet. When this information proved inaccurate and did not work, he tried to resort to blackmail, with love letters the Duke had sent him. It is revealed that they had an affair (what the Duke calls a summer dalliance), when the Crawleys were staying in London. However, the Duke stole his letters back from Thomas and destroyed them.
The new heir Matthew Crawley arrives and a local man, Molesley, is hired to be his valet. Thomas is furious that he was not offered the job.
Thomas later mistakenly makes an advance on Kemal Pamuk, a Turkish envoy who is staying as a guest for a hunt, but Kemal slaps his hand away and says he will tell Lord Grantham if Thomas does not tell him where Mary Crawley's room is. Thomas agrees and takes him to her room that night. The next day he is shocked to find Kemal dead in his own bed. He is one of the few people who knew that Kemal was in Mary 's room the night he died, but it is uncertain if he knows that he died there. He does relate what he knows to O'Brien .
Thomas realizes that his fellow footman William has feelings for kitchen maid Daisy and is planning to ask her to go to the fair. Thomas maliciously asks her first. He shows her how to do the latest dances. Daisy has a crush on Thomas, and Mrs. Patmore tries to tell her that Thomas isn't a ladies man, but naive Daisy doesn't understand why that isn't a good thing. Thomas also makes a comment about William's mother who has died, which results in a fight.
Thomas remains extremely annoyed that he had been passed up for the position of Lord Grantham's valet by "Long John Silver", which is what he calls John Bates when talking with Miss O'Brien about the new valet. He is always at odds with John. Bates catches him stealing wine and threatens to tell Mr Carson, unless Thomas stops insulting William. Thomas and O'Brien attempt to get him fired for theft by planting one of Robert's snuff boxes in his room, but Anna warns him, and he replaces it without informing on them. They later try accusing him of being the one who has been stealing wine. He and Ms O'Brien get Daisy to lie to Mr Carson. But Daisy feels guilty and admits that she lied, and then later when Molesley sees Thomas "replacing" Carson's wallet, that he found, back into his jacket, Carson tells Lord Grantham, and they agree to fire Thomas.
Thomas realizes that his days are numbered, so he has pre-emptively asked Dr Clarkson about joining the army medical corp., to train as a medic, which will also keep him out of active military service as war is looming. He hands in his notice, and everyone is happy to not have the drama of dismissing him.
The First World War (called the Great War) is going on and Thomas who has enlisted in the army as a medic is in the trenches, alongside Matthew Crawley.
Despite being a medic, Thomas finds himself still under fire on the front lines. He sees a fellow medic, just beside him, get shot in the head and die. He holds a lighter above the trench wall one night in order to get his hand shot, thus effectively removing himself from the front lines.
Thomas in the trenches about to get himself intentionally shot in the hand.
Through this action, he gets sent back to Downton Abbey, where he begins to work in the local hospital, alongside Lady Sybil who is working as a nurse.
Thomas developed feelings for a patient, Lieutenant Edward Courtenay, while Edward was recovering from gas-blindness. This is one of the first times Thomas is seen with a very kind and caring side. After being told that he was to be moved out of the hospital to make room for newer, wounded patients Thomas and Sybil are both concerned for him and try to persuade Dr. Clarkson to allow Edward to stay. Edward committed suicide with a razor he sneaked into his bed. Thomas is devastated, and is left crying, alone again. It is this incident which prompts Isobel Crawley to persuade Cora to turn Downton Abbey into a convalescence hospital for the duration of the war.
As Cora is at odds with Isobel, who is trying to run the place, O'Brien suggests that Thomas be made the manager of Downton, as he knows medicine, knows the house, and will automatically hold Cora in respect. Carson is not pleased as this makes Thomas his superior.
After the war Thomas tries to make it as a black market businessman, but he foolishly spent all of the money he had saved buying from a man he had only briefly met in a bar. He bought high-end food stuffs that looked like quality goods, but turned out to be fake or adulterated. He gives samples to Daisy to cook a cake for Mrs. Patmore. She will test it to judge the quality of Thomas's goods before they place orders with him, but the results are disastrous. Thomas goes to where he is keeping the goods and destroys them in a fit of rage. He realizes that he will be forced to return to Downton abbey as a footman.
John Bates is imprisoned for his wife's murder, and Lord Grantham needs a replacement valet. He is not convinced that Thomas should get the job, because of the past, even though he served well in the war, and seems to have reformed. O'Brien advises Thomas to take something of his lordship and then find it and return it, to prove his trustworthiness. Thomas lures Lord Grantham's dog Isis away and puts her in a shed. There is a reward and Thomas anticipates that, as well as the glory of "being a hero by finding her". However, in the Christmas Special, when he goes out that evening looking for her, he finds that Isis has gone missing from where he'd hidden her, he spends all night looking for her, getting muddied and frustrated; but it turns out that she was found and has been returned by a child from the village. Lord Grantham, walking out early in the morning with Isis, is so impressed by Thomas's effort to find his dog that he decides Thomas has changed and is convinced to give Thomas a trial at being his valet, until John can be released from his incarceration, much to Mr Carson's surprise and doubt.
At the Servant's Ball at Downton, Thomas asks the Dowager Countess of Grantham to dance, which she is quite pleased to do.
By 1920 Thomas is working as valet to Lord Grantham, and he is angry when he is told by Molesley that Matthew will not be bringing a valet to Downton. He worries that he will have to do all the work, as Robert will allow no new hires. Thomas instigates Daisy to go on strike over the fact that a new kitchen maid hasn't been hired, but tells her not to say that he put her up to it.
Sarah O'Brien gets her nephew Alfred Nugent hired at Downton to work as a footman. Thomas and Carson have refused to have anything to do with Tom Branson, so Alfred has been helping him as well, taking care of his clothes and checking that he has everything. Later Alfred is being valet for Matthew, and, despite the fact that Thomas hadn't wanted the extra work, he is angry that he wasn't asked to do it. Sarah O'Brien is fond of her nephew, and wants to see him succeed. She has considered Thomas a friend, and even told her secrets to him. She asks Thomas to teach Alfred to be a valet to Matthew Crawley. Thomas absolutely refuses. Thomas had struggled, worked and schemed for 9 years to rise to the level of valet in a noble house. Alfred is a barely experienced footman, and Thomas sees it as an insult that he could just fall into the job in a matter of weeks. In Thomas's hearing, O'Brien tells Alfred that he is not vain like Thomas.
Thomas then sabotages Alfred's efforts to clean a spot off of Matthew's tailcoat, resulting in a hole being burned through it. Thomas convinces Lord Grantham that this is proof of Alfred's being not ready for the job. Thomas repeatedly insults Alfred, and Sarah and Thomas each repeatedly try to damage the reputation of the other. O'Brien hides all of Lord Grantham's dress shirts and Thomas gets blamed for losing them. When he confronts her about it, she tells him to keep his histrionics to himself, and later when the shirts mysteriously are returned, she just tells him to go and get his lordship into his pajamas and dismisses Thomas's threats about if anything like this happens again (Thomas after this hides a couple so as not to be caught out again). Thomas knows it was O'Brien or Alfred. He starts a rumour by telling Molesley that Sarah is going to leave Lady Grantham's service.
When Mr Carson tells her of the rumour, she later learns from Molesley that Thomas started it, she knows it wasn't a mistake. She confronts Thomas and threatens him that someway she is going to make sure that things will be wrong for him.
In 1920 a handsome new footman, James, is hired and Thomas feels an immediate attraction to him. Sarah sees this. She then begins acting as if their feud is now in the past. John Bates has been released from prison. Thomas is still hoping to remain valet, as he is told that Carson is "sorting things out", but Robert just wants Bates to rest before he comes back to his job.
Sarah O'Brien, in an attempt to get Thomas fired, is leading him to believe that James has feelings for him. She encourages James to learn from Thomas and to not say anything when James feels that Thomas is being overly familiar. When James is asked to wind the clocks, O'Brien calls Thomas the clock expert and tells James to get him to show him how. James is uncomfortable with Thomas's familiarity, but he goes along with it, as Sarah leads him to believe his position could be in jeopardy if he doesn't. Sarah also tricks Thomas into believing James has feelings for him, telling him that he won't stop talking to Alfred about him.
When Sybil dies in childbirth, Thomas is reduced to tears, and Anna comforts him outside. He tells her how they worked together during the war, and she was one of the few people that ever cared about him. James is talking to Thomas about how Mr. Carson seems to favour Alfred for the job of first footman. Thomas impulsively says, "Well, I love you."
Thomas goes into James's room when he is asleep and kisses him, thinking his feelings will be returned. James awakes and is very angry, reacting violently and indicating he feels nothing for Thomas, which leaves Thomas shocked and upset. To make matters worse, Alfred witnesses this, but Thomas says that he is nothing and no one will believe him. James throws him out, and he sees Alfred, glaring at him from a doorway. O'Brien encourages Alfred to tell Mr. Carson.
When Mr Carson finds out, Thomas seems to accept that he has to leave. Mr. Carson tells him that Mr. Bates will be taking over the next morning, as valet to Lord Grantham, and he says that Thomas will have to leave Downton, but that he will be given a good reference. Thomas defends James, saying none of this was his fault. Thomas says he felt an attraction to James and thought that James was returned it, but he was wrong. According to Mr Carson, James has every right to report Thomas to the police. Mr Carson calls Thomas "foul" because of his attraction to men, but despite everything, Thomas sticks up for himself saying "I'm not the same as you, but I'm not foul".
James is satisfied that Thomas will be leaving, but it is not enough for Sarah O'Brien. She tells James that he must insist that Thomas be made to leave without a reference, otherwise he is to threaten to tell the police of what Thomas has done, and have him sent to prison. Lack of a reference would make it almost impossible for him to find another job. She tells James that unless he insists, that someone like Thomas cannot be allowed to go to another respectable position, people will think that he is sympathetic, and then they might suspect him of encouraging Thomas's advances. Thomas is devastated and feels he has been "well and truly beaten". Carson sees no option, but to refuse a reference, as otherwise the intervention of the police would cause gossip and scandal. Carson allows Thomas to stay a few days so he can work out his situation and later that evening is found outside by Mrs. Hughes, crying. When she ask Thomas what is the matter, he refuses to tell her upon the bases that she will be "shocked and disgusted" but after hearing this she insist that she will "have to hear" what is upsetting Thomas and he reveals to her what has transpired. Later Mrs. Hughes sticks up for Thomas to Carson telling him that James unintentionally flirted with Thomas to help himself get in good terms with the staff and that she did not find it right that Thomas should be ruined by this as he served and was wounded for the King and their country. She also admits to Carson that Thomas is not the first homosexual she has come across.
It is only the intervention of John Bates who not only takes the matter to Lord Grantham, but uses information he gets from Thomas to force Sarah O'Brien to make James take back his threat. Bates overhears bits of what is going, and he goes to Mrs. Hughes for the whole story. He tells Anna that he can't let a man have his life taken away. Thomas believes that he is beaten. Despondent because of James's betrayal and that he will have no reference after 10 years service, Thomas considers immigrating to Bombay, where he has a cousin, and can more likely get a job. He says that he likes the sun. However, John Bates gets Thomas to give him something to pressure O'Brien to make the situation right. Thomas tells him to repeat the phrase "her ladyship's soap". Thomas is very much surprised at John Bates helping him. John Bates however, had only thought to get him a reference, and he is not entirely pleased when Lord Grantham decides to let Thomas stay.
Thomas also appears to be quite talented at cricket, Lord Grantham noting that he had gotten most of the house team's runs in the 1919 match. He plays extremely well in 1920, and is again praised by Lord Grantham. Fortunately for Thomas, Lord Grantham doesn't want to lose his most talented player for the yearly cricket match. And so he is given his current position of under-butler. Thomas had been close friends with O'Brien, "thick as thieves" Lord Grantham calls them, and he is surprised when he learns they have had a falling out. Thomas is playing in the yearly match when the police come to question him. Alfred, learning that Thomas was going to be allowed to stay, had called them. However, Lord Grantham persuades him to tell the police that it was a mistake, that he saw some horseplay and misinterpreted it, as he was drunk at the time.
More than a year after these events, in the 2012 Christmas Special, James at first still appears uncomfortable around Thomas, and didn't want to be seen to be alone with him or even accept the gift of a drink when Thomas offers to buy everyone one. Thomas is still in love with James, despite everything that has occurred. Alfred confirms that Thomas won't allow a word to be said against James. Thomas also lends a hand when James is doing something difficult. At the fair Thomas follows James, as he knows that he has had too much to drink.
Whilst at Thirsk fair, which most of the staff attends, James wins some money in a bet on a tug of war match that both James and Thomas take part in. Later, whilst James is walking alone, two men attempt to rob him. Thomas appears and steps in to protect him and in result, is beaten and robbed in his place, after James runs away and leaves him there. James fetches Dr. Richard Clarkson and some of the other staff for Thomas and stays silent whilst Thomas fails to say what really happened, and so avoids telling everyone that James left him alone to face the two men and get beaten.
James later goes to see Thomas in his room to ask if he is all right. James says that Thomas was "brave" and that he feels bad for leaving him. Thomas reveals that he was following James that day as he had seen that James had had too much to drink. When James asks why he was doing this Thomas says that he "knows why", implying that he still has feelings for James. James says that he can never give Thomas what he wants, and Thomas says that he understands that, but would like them to be friends. James says he can do that if it is only being friends, and the scene ends on them chatting over a newspaper.
Thomas reports on Nanny West out of spite at her presuming to give him orders and his trying to bond with Sybbie. He tells Lady Grantham that he thinks Nanny West is neglecting the children, leaving them unsupervised. Lady Grantham surreptitiously checks up on the Nanny and Thomas's warnings prove well founded when she overhears West coldly insulting Sybbie because of her parentage. West is sacked immediately and Cora praises Barrow for his help.
After O'Brien's departure, Thomas seemingly forms a new partnership with her replacement, former maid Edna Braithwaite, as they frame Anna for a mistake of Edna's. Later, he spies Edna talking to Tom Branson, and later finds her singing in the boot room. She remarks to him that he should be grateful to be in her good graces. But after her scheme of seducing and blackmailing Tom is exposed by Mrs Hughes, Thomas confronts Edna and they exchange insults. Thomas is not affected by Edna's words, and calls her a "manipulative little witch" and expresses his happiness that her schemes have come to nothing. He goes to Lord Grantham and reveals he has a candidate he'd like to put forth.
The new lady's maid of Lady Grantham, Phyllis Baxter, shares some past with him. John Bates wonders what she sees in him. Thomas has her spy on the people downstairs and upstairs, telling her not to make enemies as that was the mistake of O'Brien. He becomes particularly persistent when he hears something bad has happened to Anna, making Baxter uncomfortable. But she remains in his power.
When Robert travels to America to visit his in-laws, he takes Thomas with him instead of John Bates. Thomas returns to find Baxter having formed a bond with Joseph Molesley. By 1923, he has formed a greater resentment of having to serve on Tom Branson, who would have been beneath him had he still been the chauffeur. He almost gets into an argument with Branson about where to sit in the car when they are going to join the family and other servants in London, which is prevented from happening by Ivy Stuart. Previously, Barrow had seen Branson giving a private tour of the house to Sarah Bunting. He reports this to Lord Grantham, implying the possibility that Miss Bunting might be Tom's lover.
Thomas tightens his grip over Baxter, threatening to go to Lady Grantham and reveal her secret. He is however surprised when he attempts to do so that Lady Grantham has already learned about Baxter's criminal past (Baxter had told her at Mr Molesley's urging before Barrow could). Cora scolds him for having known about her past and concealed it. He tries to reason he wanted to give her another chance, but Cora reminds him that should've been her decision, not his. She warns him that his career as well as Baxter's is now in question, especially if Cora learns he has been using this knowledge for his own benefit. Yet after saving Edith from a fire in the house, he immediately earns Cora's favor again and his job is secure. He does later tell her secret to Molesley, who refuses to believe it is that simple for her to be a thief.
Jimmy confides in Thomas after he receives numerous romantic notes from Lady Anstruther, his former employer. He tells Thomas that the latter shouldn't worry about Jimmy's romantic exploits, as one day he'll be a good boy and settle down and that's what they'll all do one day. Thomas remarks that they don't all have the option, hereby foreshadowing his frustration with not being 'like other men' and longing to be more like them, which comes more to the foreground later on in the season. Later in the episode, when Lady Anstruther shows up and lures Jimmy to her room, Thomas agrees to stand guard for him. They spot Lady Mary having secretly spoken to Lord Gillingham. Thomas remarks that she isn't very lady like after all. Jimmy tells Thomas he sincerely appreciates his friendship, indicating how far they've come since their misunderstandings of season 3. However, Thomas's concern for Jimmy and his sigh as Jimmy leaves for Lady Anstruther's room confirm that Thomas's feelings for Jimmy haven't changed. Unfortunately, due to the fire Thomas rushes to help Edith while Lord Grantham walks in on Jimmy and Lady Anstruther. After being dismissed, Jimmy and Thomas have an emotional farewell. Jimmy tells Thomas he could never have imagined being friends with a 'man like him', but that they have been good friends and that he hopes Thomas finds some happiness. Later on, Thomas talks to Anna and expresses a desire to be more likable, and she expresses sympathy with him.
Encouraged by his desire to be 'more like other people' and hoping this will make him happier, Thomas begins making a number of phone calls, inquiring about a service called "Choose your own path". He claims to Carson that he has to go see his father who is ill, but instead uses his time off to go to London to receive what is later revealed to be electroconvulsive therapy in order to change his sexuality. Upon returning from London, he continues to show an unhealthy interest in what's going on with Mr. Bates and Anna regarding the murder of Mr. Green. Later on, Ms. Baxter hears a grunt coming from the bathroom. She realizes it's Thomas and asks if she should fetch a man to help him. Sobbing, Thomas opens the door and states that there's isn't a man in the house who'd help him. Baxter tries to get inside and spots a medicine box with needles. Later on she confronts Thomas, saying that she knows it wasn't his father who was ill but Thomas himself, and that he went to London to receive treatment and is now continuing it himself. She is told by Thomas to mind her own business. As time passes, however, Thomas starts looking more and more sickly, spurring several people, including the Dowager Countess, to remark on his ill demeanor. After discovering the article in the London Magazine advertising 'Choose Your Own Path', Baxter tells Thomas that she feels sorry for what he's put himself through, indicating that she realizes he's taking some treatment to 'cure' his homosexuality. Thomas angrily tells her not to pity him.
Later on, however, a distressed Thomas asks Baxter for help, revealing that the spot where he inserted the syringes has become infected. He confesses to her that he doesn't know what to do, and Baxter tells him to go to the doctor's immediately. Thomas tries to confess to her that he wrote a letter to the police telling them that she knew more about the murder of Mr. Green, but Baxter interrupts him and says she already know that he's done that but is still willing to help him. They go to Dr. Clarkson together. Dr. Clarkson reveals that Thomas was only injecting himself with a solution of saline, which should be harmless, but that the solution wasn't sterilised and therefore caused the infection. After asking him what he was trying to do with it, Thomas admits that he was trying to change his sexuality, after which Dr. Clarkson gives him a speech, telling him to accept himself. Upon walking away from the Doctor's office, Baxter tells Thomas that she won't mock him for falling into the trap of the quack treatment, but rather thinks he's a very brave person for putting himself through all that just to get what he wants to achieve. Thomas visibly warms to her after her helping out and calling him brave, and tells her that she's 'a daft one'. After this, their relationship is much improved.
Thomas is a closeted gay man, by necessity as a homosexual act was a criminal offense at the time, punishable by imprisonment. This has made him reserved and aloof. He tells Edward Courtenay, the blinded wounded soldier that he comes to have feelings for when he works in the hospital during the war, that he has been pushed around all of his life because he is different. He tells Carson that when one is like him they must judge if someone else is interested by signs, as no-one dares to speak aloud about it. None of the relationships that we have seen have gone well for Thomas. He had an affair with the Duke of Crowborough, who then refused to hire him as his personal valet. He tried to resort to blackmail, but the Duke stole his letters back from Thomas, and destroyed them. Thomas later makes an advance on Kemal Pamuk, a Turkish envoy, who threatens to tell Lord Grantham if Thomas does not tell him where Mary Crawley's room is. Later, it is implied that he falls in love with Edward Courtenay, who commits suicide. Thomas is misled by O'Brien into thinking that James is gay, and tries to kiss him while he is sleeping, but James is horrified. Still Thomas is not ashamed of what he is. Carson says that he is revolted and that Thomas has been twisted by nature into something foul. Thomas tells Mr. Carson that they are not the same, but he is not foul.
Thomas has an affinity with clocks, and he calls them living things. He likes to get people in trouble, often by presenting his own intentions as good and implying the worst while not knowing for certain the truth.
Thomas and Sarah O'Brien are called "thick as thieves". In the beginning they are close. They both seem to hold people in disdain and enjoy scheming and manipulating others. Thomas creates his own problems with O'Brien by refusing to teach Alfred. She was the closest person he had in Downton to a friend; she had put her job on the line for him trying to oust John Bates and telling him her secrets. Thomas refuses to help Alfred out of pride in his own importance. He has shown himself to be capable of being very cruel, for example, he asked Daisy to go to the fair with him just to upset William Mason who was planning to ask her. And he is capable of telling very nasty insults. Also he later made comments about William's mother after she had died, which resulted in a fight. After John Bates is found guilty of his wife's murder and sentenced to hang, Thomas's first comment to O'Brien is, "Now there'll have to be a new valet won't there?" O'Brien replies that she doesn't often feel selfless, but around him she does. However, as the series progressed Thomas appeared to learn some humility, after his set backs in romance, his experiences in the war, and in trying to speculate in the black market, and his attitude toward working as a footman became much more positive. Fans speculate that Thomas's failed relationships and frustrations over the constant oppression of his gayness and never being able to explore who he is freely, has made him bitter and left feeling unloved, causing him to lash out against even those closest to him and hold a high sense of false pride as a defense mechanism. Thus, he is still not above using crooked methods to further his own career, such as when he locked Isis in a shed.
To begin with Thomas is good friends with Sarah. They are as "thick as thieves" according to Lord Grantham. The two of them are constantly plotting to get John Bates thrown out, although none of their schemes are successful. She has considered Thomas a friend, she plotted with him to get Bates fired, and he even knew her darkest secret.
Thomas and Sarah become bitter rivals when Sarah's nephew Alfred Nugent comes to Downton to work as a footman. He didn't always liked being a footman. Sarah is fond of her nephew, and wants to see him succeed. She asks Thomas to teach Alfred to be a valet to Matthew Crawley. Thomas absolutely refuses. Thomas had struggled, worked and schemed for 9 years to rise to the level of valet in a noble house. Alfred is a barely experienced footman, and Thomas sees it as an insult that he could just fall into the job in a matter of weeks. Thomas then sabotages Alfred's efforts to clean a spot off of Matthew's tailcoat, resulting in a hole being burned through it. Thomas convinces Lord Grantham that this is proof of Alfred's being not ready for the job. Thomas repeatedly insults Alfred, and Sarah and Thomas each repeatedly try to damage the reputation of the other. Sarah takes a stack of Robert's dress shirts and hides them so that Thomas is blamed for losing them, when his lordship cannot dress or dinner. When Lady Edith is left at the altar, Sarah says that she wouldn't be able to handle the shame. Thomas makes the nasty comment that it's a good thing no one has ever asked her.
When Thomas starts a rumour that Sarah is going to leave Lady Grantham's service, it is the last straw, and Sarah vows to get revenge. She tells Molesley to tell him that she may make some honest mistakes of her own and later threatens Thomas that soon everything will be "all wrong" with him. She plans to get him fired with no chance of a good reference and therefore almost no chance getting another job. To do this she makes Thomas think that Jimmy Kent has romantic feelings for him. When Jimmy tells Sarah that he is uncomfortable with how familiar Thomas is, she convinces him not to do anything. This ends in Thomas kissing Jimmy whilst Alfred happens to see everything. In reaction to this, Sarah talks Jimmy into asking for Thomas to be sacked and Alfred into calling the police, although ultimately her schemes come to nothing and Thomas keeps his job.
To begin with, Thomas is extremely annoyed that he had been passed up for the position of Lord Grantham's valet by "Long John Silver", which is what he calls John Bates when talking with Ms O'Brien about the new valet. Throughout the first series, he is always at odds with John, trying to get him fired for theft so that he could become a valet.
During the second series, the animosity between Thomas and John is not seen much, due to many reasons, one being that Thomas was in the Army Medical Corps for a short time and then John is arrested tried, and sentenced to hang, for the murder of his ex-wife Vera. Thomas wins Lord Grantham's favour and Bates's job as valet when he takes Lord Grantham's dog, so that he can be a hero by finding her. Isis has gone missing from where he'd hidden her, and he spends all night looking for her. Lord Grantham, however, is so impressed by Thomas's effort to find his dog that he ends up giving Thomas a trial as his valet.
In Series 3, Thomas still feels animosity toward John. Anna is renting out Vera's residence that was Bates's mother's house, but Thomas says that a murderer shouldn't profit from his crimes. When Bates is released from his wrongful conviction, Thomas is bitter that his former rival has returned. Thomas still hopes that Lord Grantham will decide to retain him as valet. He makes the comment that "It's Mr. Barrow now, Mr. Bates. And yes, I'm still here, and busy as a bee." However, it is increasingly obvious that Lord Grantham expects Bates to return to the job.
He is subsequently embroiled in the scandal with James the footman and almost accepts it as inevitable when, during Episode 8, Mr Carson tells him that John will be returning to his former job the next morning. To Thomas's great surprise, John decides to strike up a temporary alliance against Ms O'Brien with him (which Anna heartily disagrees with). John Bates has found out the story from Mrs. Hughes and learned that Thomas could possibly be sent to prison for criminal assault, a fate he would wish on no man. Though Thomas has schemed against him for years and plotted to get him fired, he has to help. Bates tells Anna that he knows how it feels to find yourself trapped and feeling your control of your own life slipping away. He gets Thomas to tell him something that will make Sarah O'Brien stop pushing James the footman into threatening to go to the police, if Thomas is not dismissed without a reference, due to his homosexuality. When Lord Grantham subsequently decides to keep Thomas at Downton, he discusses it with John. He dislikes the idea that Thomas will be staying on. The antagonism between the two appears as John comments "Couldn't Mr. Barrow just stay until after the match, milord, and then go?" and then further saying "He might not want to stay, milord, after the unpleasantness." Later, Bates tells Anna that he was a fool, and, if he had just stayed out of it, Thomas would have been out of their lives forever. Overall, the relationship between Thomas and John is not exactly hate, but it's not a fully-fledged friendship, either. Thomas is amazed that John Bates his long time rival will help him. He says that prison has changed him.
Thomas's relationship with Daisy was rocky, at first. She was in love with him, blatantly smitten and he only bothers with her to bother the other footman, William Mason. He manipulates her and uses her against John Bates, getting her to lie to Carson several times.
She eventually gets over him, finds her voice and starts telling him to stop "being so unkind." She is the only one who does not see Thomas as an unkind person, just that he acts unkind sometimes (sometimes meaning nearly always).
They become friends as time goes by, when he comforts her and asks what's wrong when she's crying over Alfred leaving. He recognizes the mistakes she's made (he's just made them himself) and tries to comfort her. When Mrs. Patmore calls Daisy back into the kitchen, she says, "And Mr. Barrow, you quit teasing her!" To himself, Thomas comments, "I wasn't, actually." And for the first time, he wasn't. He was actually being kind to her.
Thomas developed feelings for Lieutenant Edward Courtenay while Edward was recovering from gas-blindness. This is one of the first times Thomas is seen with a kind and caring side. Edward is despondent and fears he will never see again. Thomas tells him that he has to fight and get through this. Thomas reveals that he himself has always been pushed around, because he was different. When Edward asks him how he is different, he tells the Lieutenant that the reason is not important, and it is not shown that Edward shared Thomas's feelings. After being told that he was to be moved out of the hospital to make room for newer, wounded patients; Edward committed suicide with a razor he sneaked into his bed. Thomas is seen crying, alone once again.
Sybil seems to be the one member of the Crawley family whom Thomas likes. They worked together during the war when Downton was a convalescent home and Sybil works there as a nurse. They both like and are concerned about Edward Courtenay and try to convince Dr. Clarkson to let him stay on instead of being transferred. After Lady Sybil's death, Thomas is seen crying and when comforted by Anna, he says that not many in his life have been nice to him, and that she was one of the few. Perhaps because of his bond with Sybil, Thomas is close to her daughter, speaking kindly to her and helping defend her from Nanny West's cruel words by telling West off to Cora.
In 1920 Thomas develops an attraction to the handsome new footman Jimmy Kent. He begins to behave very uncharacteristically. He goes out of his way to see and talk to him. Thomas also begins smiling a lot more. Thomas comes to his door, while Jimmy is getting dressed. Thomas starts to think that Jimmy has feelings for him. This is partly wishful thinking and mostly Sarah O'Brien's efforts to lead Thomas to believe that Jimmy returns these feelings, in an attempt to get revenge on Thomas by getting him fired. At the same time, O'Brien encourages Jimmy to learn from Thomas, as he has Lord Grantham's ear, and can further his career, and to not say anything when Jimmy feels that Thomas is being overly familiar. O'Brien has Jimmy go to Thomas to show him how to wind the clocks. Thomas holds Jimmy's hand while standing behind him with his other hand on Jimmy's shoulder. Thomas frequently touches Jimmy, who is uncomfortable with Thomas's actions, but he goes along with it, as Sarah leads him to believe his position could be in jeopardy if he makes a fuss about it and that it is a good thing that Thomas likes him. Sarah tells Thomas that Jimmy has a crush on him and that he won't stop gushing to Alfred about Thomas.
Jimmy comes to Thomas with his problems. He wants the job of first footman, but thinks that Mr. Carson favours Alfred. Thomas impulsively says, "Well, I love you." That night Thomas goes into Jimmy's room when he is asleep and kisses him passionately, thinking his feelings will be returned. Jimmy awakes and is very angry, reacting violently and indicating that he feels nothing for Thomas. He throws Thomas out of his room leaving him with tears in his eyes standing in the hallway.
To make matters worse, Alfred sees it and tells Mr Carson who says that Thomas will have to leave Downton, but that he will be given a good reference. Thomas defends Jimmy, saying none of this was his fault and that he was an innocent victim. Thomas says he felt an attraction to Jimmy and thought Jimmy returned it, but he was wrong. According to Mr Carson, Jimmy has every right to report Thomas to the police. Mr Carson calls Thomas "foul" because of his homosexuality but despite everything, Thomas sticks up for himself saying "I'm not the same as you, but I'm not foul".
Jimmy is satisfied that Thomas will be leaving, but it is not enough for Sarah O'Brien. She tells Jimmy that he must insist that Thomas be made to leave without a reference, otherwise he is to threaten to tell the police of what Thomas has done. No reference after 10 years would make it almost impossible for him to find another job. She tells Jimmy that unless he insists that someone like Thomas cannot be allowed to go to another respectable position, people will think that he is sympathetic and then they might suspect him of encouraging Thomas's advances. Thomas is devastated by Jimmy's betrayal. He still believes that Jimmy himself would not be capable of this and that some one has put him up to it. He even loses the will to fight for himself, as he later tells Bates, he feels as if he has been "well and truly beaten". Carson sees no option but to refuse a reference as otherwise the intervention of the police would cause gossip and scandal. It is only the intervention of John Bates who not only takes the matter to Lord Grantham, but also uses information he gets from Thomas to force Sarah O'Brien to make Jimmy take back his threat, that allows Thomas to keep his job. Jimmy is unsure about Thomas staying, but Robert tells him at the same time that he has been promoted to the job of first footman.
More than a year after these events, in the 2012 Christmas Special, Jimmy at first still appears uncomfortable around Thomas, and doesn't want to be seen alone with him or to even accept the gift of a drink when Thomas offers to buy everyone one. Thomas is still in love with Jimmy, despite everything that has occurred. Alfred confirms that Thomas won't allow a word to be said against Jimmy. Thomas, despite his bad hand also lends help when Jimmy is doing something difficult like moving a heavy trunk.
At the fair in Thirsk, Thomas follows Jimmy, as he knows that he has had too much to drink and is carrying the money he won in a bet. Later, whilst Jimmy is walking alone, two men attempt to rob him. Thomas appears and steps in to protect him, and tells Jimmy to run. Thomas is beaten and robbed in his place, after Jimmy runs away and leaves him there. Jimmy fetches Dr. Richard Clarkson and some of the other staff for Thomas and stays silent whilst Thomas fails to say what really happened, avoiding telling everyone that Jimmy left him alone to face the two men and get beaten.
Jimmy later goes to see Thomas alone in his room and ask if he is alright. Jimmy says that Thomas was "brave" and that he feels bad for leaving him. Thomas disagrees and says that he should have run, if he didn't get away what was the point of Thomas doing any of it. He reveals that he had been following Jimmy that day as he had seen that Jimmy had had too much to drink. When Jimmy asks why he was doing this, Thomas says that Jimmy "knows why", implying that he still has feelings for Jimmy. Jimmy says that he can never give Thomas what he wants, and Thomas says that he understands that, but would like them to be friends. Jimmy says he can do that if it is only being friends and the scene ends on them chatting over a newspaper.
By 1922 they begin to show signs of their new-found friendship with Thomas showing no outward signs of his previous feelings for Jimmy. They often play cards together and despite whatever Thomas may still feel for Jimmy, he remarks before he accompanies Lord Grantham on a trip to America that he hopes to see Jimmy with a girl when he returns.
“ Imagine Carson without a footman, like a ring master without a pony. ”
Julian Fellowes the writer of the show has said that Thomas is not as smart as he thinks he is.
Speaking about Thomas's relationship to Sarah O'Brien, Rob James-Collier calls her Miss O.B. and says that Thomas and O'Brien met through the common bond of smoking together outside to avoid Mr. Carson. He describes both of them as ambitious and says that they will stop at nothing to get ahead, and that Thomas opposed Alfred becoming a valet, because, as he was being rapidly pushed by O'Brien, Thomas feared that Alfred might be coming after his own job next. Collier believes, in their escalating feud, that O'Brien will always be willing to go one step further and that's what makes her scary. He feels that even if Thomas were able to forgive her and tried to reconcile it would not be in her to do it.
Julian Fellowes relates that the character of Thomas is based on a dresser in his "theatrical past".