|First appearance||Caroline's First Day|
|Last appearance||The Special|
|Portrayed by||Karl Theobald|
|Relatives||Joanna Clore (mother)
Donald Twatt (father)
Guy Secretan (half-brother)
Martin has had a rather unhappy life. He is unloved by his mother, who wants the fact that he is her son kept a secret as it would reveal her true age if discovered, and his parents are divorced. His father was a newsagent called Donald Twatt, but they changed Martin's surname. In an episode of series 2, Martin hires a private detective, and eventually, Martin and his dad meet when Martin accidentally knocks over his father's present for him. He grew up in a very small town, which Martin claims had only one black person in it called Chas, who had spiky green hair. As a result he used to think that black people were, "Just a kind of giant Muppet". He claims to be 'all right' now. At school he was nicknamed "Chuzzlewit", after Martin Chuzzlewit, which was shortened to "Tit", then lengthened to "Titbrain". But Martin still sees this as compliment due to the Martin Chuzzlewit origin.
He is a candidate for the part one examination for membership of the Royal College of Physicians, the first step to promotion to registrar and eventually consultant positions. At the beginning of the series he has already failed the exam an unspecified number of times. His anxiety over the exam and eventual failure are a theme of the first series. He worries obsessively that failure at the exam will prevent him from specialising and end his career with the hospital.
His half-brother constantly bullies him, often calling him "Fartin", and telling him he is the weaker of the two of them. Guy has mocked him verbally, physically and mentally, from making fetch squash balls thrown at him down a hospital corridor, to strangling him against a wall. However Mac often comes to his rescue. He was also friends with Dr. Angela Hunter, and during her funeral, performed a mime to express his feelings about her. Although he is unaware of this, Kim Alabaster and Naughty Rachel in HR often call him "Martin Dear, he's so Queer", but this is mainly to irritate Karen Ball another worker in HR who has a crush on him.
He has very little in the way of a love life. He has deep affections for surgical registrar Dr. Caroline Todd, but Caroline sees him as nothing more than a good friend. Martin still does have affections for Caroline, and proposed to her, with the help of Karen, Kim and Rachel as cheerleaders, but Caroline turned it down, after she realised the name they were spelling went, "M, A, R" not "M, A, C". He does however attend Caroline's wedding to Mac.
He has also had an encounter with Karen, however he decided to leave her because their relationship was becoming too physical. However, when he tries to dump her, he always changes his mind. He once left a message on Karen's mobile phone, changed his mind, and in a bid to stop Karen from listening to it, put it in his mouth and swallowed it. The relationship did end however, when she heard that Martin was seeing a prostitute (although they never had sex, he was acting for her as sort of involuntary pimp). The relationship began again when he punched her new boyfriend to win her back.
He also has money problems. He once became a nude model for a hospital painting class, where one of the students, liaison officer Sue White claimed he had a large penis. However, he did once win £10,000 on a lottery scratchcard (£7,000 of which he gave to the cashier after he made a deal with her because he did not pay for the scratchcards upfront). He is also constantly failing his medical examinations to his mother's embarrassment. He drinks Guinness (which he hates) to look cool, and alcoholic drinks disagree with him in general.
Martin has twice been involved in car accidents. The first accident happened when he told Guy that they were half brothers. Guy stole an ambulance with Martin and Mac in it, and drove it over a cliff. Martin was relatively unhurt, but Mac ended up in an eight-week coma and suffered amnesia. The second accident occurred when he climbed onto a stolen camper van with Joanna on board with Dr. Alan Statham, who ended up (almost) driving it over exactly the same cliff. The last scenes show him trying to escape death yet again. Martin however manages to call the AA and rescue them. He soon gets dumped off the van. The last he ever hears from Joanna is from a postcard sent by her and Alan.
In his spare time, Martin likes to ride his scooter, an Aprilia Habana 125. He always rides it to work, despite the fact that lives directly opposite the hospital. He also likes to spend time with his best friend and fellow junior doctor Boyce. Martin is also well travelled, having visited both France and Holland. He is also circumcised, although he does point out he is not Jewish. He claims that Wayne Sleep was the best person he was compared to, the worst one being Dustin Hoffman.
Martin has always had trouble with his mother. Due to her worrying about her age, she refuses to let Martin tell anyone that they are mother and son, because everyone will know how old she is.
It is known that Joanna was not really a good mother. She did not do the things that Martin most needed, such as "Making my packed lunches" and "Making that Incredible Hulk costume for Halloween". Joanna has also tried to make it hard for him to locate his father, Donald Twatt. This was done by changing Martin's surname and moving away.
Martin still wishes that Joanna will love him, and tries to talk to her, often failing. He even managed to stowaway on the camper van that Alan and Joanna steal. When the van is teetering over the edge of the cliff, Martin calls the AA and rescues them. They soon dump Martin and go on the run, but do send him a postcard.
Boyce is Martin's best friend, and the person he confides in most, often calling each other Boycie and Marty.
They can often be seen passing the time together. They have tried finding giveaway £20 notes in bags of crisps using an MRI scanner, building towers using chocolate bars, or talking about the latest relationships.
Martin is the first person that Caroline speaks to at the hospital. She sees him being strangled by Angela, and shouting at him, telling him things like "Pluck out her nipples!"
She forms a strong relationship with Martin; however he is rather more enthusiastic about their relationship than Caroline is. He starts to fall in love with Caroline ever since she kissed her at the housewarming party. One night, he sleeps at Caroline's flat (or rather her brother's flat), he finds one of Caroline's pubic hairs in the bath, and sticks it between his teeth, which gets stuck.
He has tried to express his love for Caroline, but problems often arose. He eventually got the chance to tell her his feelings when he bought Caroline at a charity slave auction for £3,000. However, when he tries to pretend to be a bastard to impress her, the plan fails to work, and when he tells her it was partly Mac’s idea, it leads her towards his affections.
However, Martin is still very much attracted to her. After separating from Karen, he tried Caroline again. He even went as far as proposing to her, using Karen, Kim and Rachel as cheerleaders, but Caroline turned him down. Although he was rejected, he did not take it too badly, and does attend Caroline's wedding to Mac.
The only member of staff who is in any way attracted to Martin is Karen. She even goes as far as to write a poem about him. Why Karen finds him attractive is not really known, but she tries to make herself attractive. Martin is too often busy being attracted to Caroline to pay attention to Karen.
Eventually, Karen and Martin do have a relationship, which Martin tells Boyce is somewhat oversexed. Karen seems to want to do it with him constantly, which led to Martin several attempts to dump her. However, most of them failed, or Martin changed his mind at the last minute. Their relationship finally ended when Karen saw him with a prostitute which Martin accidentally became her pimp.
Before and after they discovered they were half-brothers, Guy constantly bullied Martin. He kept making insults, giving him bad or irrelevant advice, and constantly made it clear that he thought that he was going to fail his exams. Guy also persuaded Martin to drink his urine, claiming "drink my pee, pull like me" when Martin was having trouble flirting with women. However, it was not Guy's urine, Guy had taken it from the pathology lab. Guy also has the tendency to constantly steal Martin's food, either out of the staff fridge or in the cafeteria right off of his plate. When Martin did get his exam results back, Guy lied to Martin about passing them. It was left to Mac to sort the mess out. Guy still bullies Martin however.
Mac often ends up helping Martin whenever he is in trouble, or is being bullied by Guy. When Guy lied to Martin about passing his exams, Mac forced Guy to apologise after Mac poured coffee over him and banged his head repeatedly against a locker. He then made Guy and Martin hug.
Despite this, Mac still has to step in to help Martin. One such incident occurred when Guy had taped him to the toilet walls.
Because of this, Martin holds Mac in very high regard, describing him as his "best friend" to Guy when confronting him about not showing his sadness at Mac's impending death. When he learns that Mac is going to die, he cries, knowing he would never see him pass his exams. He does attend Mac's wedding, though gets disappointed when he fails to hear Mac's real name during the vows, as everyone coughs when it is mentioned.
Martin often asks Sue for personal advice, such as how to make the patients like him. Once, Martin asked her help for finding clothes for Caroline's housewarming party. After rejecting the "dead box" Sue eventually gives him a shirt with spikes on the sleeves that light-up in the dark.
At one point, Martin was threatened by Guy when he gave him the tape of him and Joanna having sex. Martin told Sue about the threat and the tape, which Sue promptly stole from him.
Sue has painted a nude portrait of Martin, which he ended up stealing from her office.
Martin does not involve himself with the rest of the HR staff, although Kim and Rachel try to hinder Karen’s attempts to make her look attractive to Martin.
He is friends with Angela, even performing a mime at her funeral, and although he does not come into contact much with Alan, he does seem to get on with him.