Make an appointment with the brilliant but socially awkward and neurotic Doc Martin. When Martin develops an aversion to blood, he abandons his career as a celebrated London surgeon and becomes the only doctor in a sleepy small town where his tactless manner soon has the whole town in an uproar.
Portwenn is abuzz with activity for the preparation of Janice and Penhale's wedding, but a medical issue could prevent Penhale from making it down the aisle. Meanwhile, Al is struggling with the demands of being best man, especially when Bert's marketing antics mean there is only whisky available at the pre-wedding party.
Martin and Louisa search for a nursery now that Janice has left, and Mrs Tishell is shocked to find out that Al has very high blood pressure. Louisa also helps with the diagnosis of a pupil, which spurs her on to explore the possibilities of a change of career. This is not welcome news for Martin, who dislikes any kind of change, even if it could be for the better. Elsewhere, Ruth is approached about selling her farm. Starring Martin Clunes, Caroline Catz, Selina Cadell and Ian McNeice.
The curmudgeonly GP is perturbed when he discovers Louisa, who is already spending much of her time away from home, has applied to take up a child and adolescent counselling course. However, achieving a work-life balance is far from the greatest of concerns for some of the Ellinghams' neighbours, not least of whom is Al, whose plans to demonstrate his business acumen are placed in jeopardy when Ken decides to close the pub. Unless Ruth agrees to serve as a guarantor, Ken will not allow Morwenna and Al to take over the establishment, so the pair arrange a race-walking event to raise funds and prove the community is on their side.
Morwenna's parents Jack and Tara pay a surprise visit, having been working as missionaries in Kenya. However, the reunion is tinged with sadness when it turns out that Morwenna's mother has liver cancer, and has decided against treatment because of her faith. Louisa's first online call for her new course does not go as planned - especially when Martin tells the lecturer exactly what he thinks - and Joe investigates a break-in at the school where nothing has been stolen.
Louisa has problems at school with Toby, Angela Sim's Nephew. Meanwhile, Al has a 'Large Whiskey' order and has to ask Bert for some help, and Mrs Tishell seems to be having a delayed onset of mourning. Elsewhere, Martin and Louisa decide to try Mel's suggestions of using amber beads to help James while he is teething.
Penhale decides to have a Police Open day to raise community awareness, but the only genuine visitor is an angry farmer who has had three of her sheep stolen. Meanwhile, Morwenna decides to take Al away for the weekend to try out Hannah's new glamping site, but the trip does not go well as Al accidently burns down the yurt. Elsewhere, James has started biting not only Louisa but other children at the nursery. Louisa speaks to Tina about it, but is surprised to find out Tina has spoken to their lecturer about it too.
It is the annual Portwenn versus Port Carran gig race and school gig festival, and this time Penhale is the umpire and Morwenna is the Portwenn team captain. However, Morwenna is forced to find a replacement rower when Eric dislocates his finger. Meanwhile, Mel Hendy goes to see Martin at the surgery worried about a rash that could be infectious, but she ends up opening up to him about her concerns over her husband's drinking. Elsewhere, Martin and Louisa arrive home to find Chris Parsons waiting for them.
Martin prepares to face his hearing, but despite having closed the practice, he finds all his patients are trying to make appointments. An American tourist who visited Portwenn previously returns to the town, hoping to research her family tree. However, she also has a medical issue, and comes to the troubled doctor seeking his advice. Louisa goes to see Chris to find out how serious the situation is, while the townsfolk take steps to show Martin how much he is appreciated. Sigourney Weaver reprises her guest role from the previous series. Last in the series.