A year after resigning his medical license, Martin finally admits he wants to be a doctor again when a woman with serious symptoms refuses to allow him to examine her.
With Martin and Louisa sharing office space, the surgery isn"t running very smoothly, so Louisa is keen to consider moving when her childhood dream home goes up for sale.
Martin spars with an herbalist who is dispensing dubious treatments to the villagers. Meanwhile, Penhale tries to rekindle his romance with Janice.
Louisa"s father makes an unannounced visit, but when it becomes clear that he is unwell, the Doc is torn between professional duty and family loyalty.
Martin and Louisa head to London so he can deliver the keynote address at the Imperial College Obstetrics Conference, but all does not go smoothly.
The news of Martin"s invitation to be the dean of Imperial College spreads through Portwenn like wildfire, before Martin and Louisa have even decided if he"ll accept it.
As the Ellinghams prepare to leave for London, Ruth counsels Mrs. Tishell on overcoming her Doc obsession, while Penhale anxiously arranges their goodbye party.
Portwenn is full of festive cheer--until Martin cancels the Santa, prompting his portrayer to show "Doc the Grinch" the magic of Christmas, with unintended consequences.
Martin's GMC report requires that he pass three refresher courses, starting with phlebotomy; Louisa is focused on her new career as a child and adolescent counselor; much to Bert's dismay, Al hires Caitlin, and confesses to his accidental proposal.
Louisa plans a special evening for Martin's birthday, which doesn't go according to plan because of Al's surprise engagement party for Morwenna.
Martin has his second GMC assessment; Buddy is missing; Ken's arrival doesn't bring good news for Al and Bert; Penhale isn't happy with the arrival of his predecessor.
Doc Martin's medical career is still under scrutiny because of his pre-existing blood phobia, and he has to pass three new courses; Louisa focuses on her new career.
Martin and Louisa attend their first fertility consultation; Penhale investigates a case of vandalism at a local surf school; Louisa prepares for her first supervised counseling session.
Mrs. Tishell's young cousin shadows her at the pharmacy for some work experience; Al decides to move in with Morwenna; Angela visits Martin's surgery and notices something wrong with Buddy.
Martin rushes to Ruth's for a medical emergency, but quickly realizes the problem is him; wedding bells are ringing in preparation for Morwenna and Al's wedding, but all doesn't go to plan, and neither does Martin's final GMC assessment.
Preparations for Janice and Penhale's wedding continue, sending Portwenn into a frenzy; Louisa and Martin are living together again.
Martin and Louisa look for a nursery suitable for James; Louisa entertains the idea of a career change; Mrs Tishell is shocked to find that Al has high blood pressure.
With Louisa gone sailing, Martin is left to look after James; Al and Morwenna organize an event to save the pub.
Morwenna's parents surprise her with a visit from Kenya, but their bad news threatens to ruin the trip; Martin intervenes when Louisa's first Skype call goes off track.
Penhale organizes a police open house but the turnout is not what he expected; James goes through a biting phase.
It is the annual Portwenn versus Port Carran race and Morwenna needs to find a replacement rower.
Awaiting his hearing, Martin has not been able to practice, but this does not stop patients from asking for medical advice.
Martin returns to Portwenn, but without Louisa, who has gone to stay with her mother in Spain.
Rachel may be able to help Martin change his ways; Louisa's return raises questions about her and Martin's relationship; Al welcomes his first fishing guests; Bert decides to try to rejuvenate trade at the restaurant.
Louisa and Martin have their first therapy session together, but neither of them expected to be given homework; Louisa is surprised when Martin agrees to let Peter Cronk do work experience at the surgery; Peter tries to boss Morwenna around.
Martin reaches a breaking point; Louisa and Morwenna persuade Martin to find Buddy a new home; Martin is not impressed by Angela's alternative approaches to medicine; Ruth finds out that Bert has been trying to make his own whisky.
Dr. Timoney advises Martin and Louisa to try to take things back to the beginning of their relationship and plan a date; Danny, Louisa's ex-boyfriend, arrives from London with seven children.
After Martin and Louisa tell Dr. Timoney about their failed date night, she questions their compatibility; Erica, the new art teacher at Portwenn school, moves in with her daughter; Louisa's happiness at finding a permanent teacher is short lived.
Martin finds himself trapped by Annie Winton, who desperately wants him to try to save her husband Jim; Louisa is worried about Martin; PC Penhale drives Louisa up to Winton Farm, where they discover Martin performing a life-saving operation on Jim.
Portwenn is buzzing with arrangements for the wedding of the Doc and Louisa; Ruth has a hard time taking care of James; the power goes out.
Ruth has a mystery admirer who unnerves her; Louisa gets in trouble with Bert when one of her students writes about getting food poisoning at his restaurant.
Martin takes baby James to playgroup, where he is forced to sing along with the other moms; Al signs up for a dating web site; Bert finds Jennifer in the bathroom with a needle.
Mrs. Tishell returns to the village; Martin has to work out what is wrong with beachcomber Lorna; Al and Morwenna have Internet dating disasters.
Martin's mother returns to Portwenn; questions about asbestos cause panic; Bert has a question for Jennifer.
Martin helps Louisa hand out awards at school; showdown between Ruth and Margaret; Mike has a shady revelation from his past.
Louisa has news for Martin; disaster hits at Bert and Jennifer's engagement party; Al has a business proposition for Ruth.
Season 5 opens with Martin coming to terms with fatherhood while dealing with his GP successor, whose competency he comes to doubt. In other events, he's devastated by the death of someone near and dear to him.
Doc Martin has to deal with the death of his Aunt Joan, demands of fatherhood, and the arrival of his Aunt Ruth.
Martin's new receptionist makes a poor first impression; Louisa and Martin find sleepless nights are taking their toll.
Portwenn Fun Day has the villagers abuzz; Martin and Louisa are not happy when Louisa's mother arrives unexpectedly.
Joe Penhale is desperate to show Maggie he has changed; Martin has to rescue Mr. Coley from a rooftop.
Bert Large's restaurant is in financial trouble and he is unable to help with the charity event for Florence Dingle's cat sanctuary.
Mrs. Tishell's crush on Martin takes a dramatic turn when, believing him to be her child, she leaves town with baby James.
Martin prepares to leave Portwenn when his relationship with Louisa fails; Martin's medical school girlfriend arrives.
Martin is unsure what to do when he hears Louisa's news, but Louisa does not want him involved; Louisa's new headmaster is exhibiting erratic behavior.
Louisa has a medical scare and goes to Martin for reassurance; Joe Penhale's brother Sam comes to town; Martin learns the surgery needs some updating.
Martin urges Louisa to slow down after he catches her moving furniture; Martin refuses a handicapped parking tag for an elderly couple when the man won't prove he is disabled.
The widow of one of Doc's patients believes her husband is trying to communicate from the grave; one of Louisa's students falls ill on a class trip.
Pauline finds out Doc is leaving; Bert organizes a baby shower for Louisa; Doc and Edith go to a conference.
Bert has another money-making scheme go wrong on Doc's last day in Portwenn, causing Louisa to go into premature labor.
A new police officer, who has narcolepsy, replaces Mark Mylow; Martin treats a girl who's been taking her mother's diet pills.
Bert quits the plumbing trade to open a restaurant, but the opening doesn't go so well when Doc notices blood on his plate and, the next day, treats many with food-poisoning patients.
Louisa's new neighbors cause problems for her, for Martin and for other residents; townspeople notice something unusual about Joe Penhale.
Louisa Glasson finds out she has a rival for Doc Martin's affections; Martin accidentally runs over a dog.
Portwenn is buzzing with news; Bert's restaurant is in trouble so his son decides to take action to save the business.
Martin needs to find a replacement vicar just three hours before the wedding; bridesmaid Isobel goes into labor.
Louisa's ex returns to Portwenn hoping for a reunion; Martin sees a patient who has a history of self-injury; Elaine's cousin, Pauline, takes a job at the surgery.
Louisa is up for promotion to head teacher, but Martin is on the board of governors and may go against her.
Martin's house call to the home of the Flint brothers leads to a diagnosis of food poisoning; Al learns that Bert is not his natural father.
Martin must treat an elderly man with a horrible smell; a local radio host appears to have a drinking problem; Julie Mitchell arrives in Portwenn.
Martin is blamed when a patient dies during an examination; Joan urges Martin to explain the circumstances surrounding Helen's death to the widower.
Martin is surprised and puzzled when his parents suddenly arrive for a visit; Martin's examination of a woman leads to a surprise diagnosis.
Martin urges Mrs. Tishell to remove the collar she's worn for years; career disagreements lead Louisa to break up with Danny; a man from the Salvation Army arrives in Portwenn.
Birdwatchers descend on Portwenn in search of a rare species; Pauline gives her notice; Bert uses the police van to take the birdwatchers on tour.
Though Martin has opened his surgery, his patients seem to treat it more as a social hangout; Martin is forced to fire Elaine for incompetence.
When a nasty stomach bug sweeps through Portwenn, Martin takes to the radio to alert residents to the danger, with unforeseen consequences.
Louisa invites Martin to the Portwenn Players Dance; Martin makes a house call to a park ranger who claims to have a six-foot red squirrel as a friend.
Martin's Aunt Joan wants to rekindle a romance with an old flame who is suffering from a life-threatening heart condition; Al tries to woo Elaine.
Martin tries to warn a woman about the dangers of sun bathing, but ends up offending her; gossip about the blood phobia circulates.