Successful surgeon Dr Martin Ellingham relocates to the seaside village of Portwenn in Cornwall; but his gruff demeanour and poor bedside manner bring him into conflict with the locals as he begins his new life as a GP.
After having therapy to save their marriage in the last series, Martin and Louisa face the challenge of living happily together with their baby James Henry. Meanwhile wedding bells are ringing for Portwenn's police constable, Joe Penhale and the Doc's nanny Janice Bone.
With Janice gone, Martin and Louisa are looking for a nursery for James. Mrs Tishell is shocked to learn that Al has very high blood pressure. Ruth is approached about selling her farm. Louisa helps with the diagnosis of a pupil, which spurs her on to explore a possible career change. This is not welcome news for Martin, who dislikes change of any kind, even if it could be for the better.
Having worked as missionaries in Kenya, Morwenna's parents, Jack and Tara Newcross, pay her a surprise visit, and are surprised by the relationship between her and Al. Morwenna is shocked to discover the real reason for her parents' return is that Tara has cancer. She has decided against treatment because of her faith. Both Morwenna and Martin think this is a foolish decision.
James is teething: nothing seems to be working, and nobody is getting any sleep. In desperation, Martin and Louisa agree to try Mel Hendy's (Rosie Ede) suggestion of amber beads. They appear to be working, until James gets a bead stuck up his nose.Mrs Tishell seems to be having a delayed onset of mourning and is "speaking to" Clive. Bert tries to offer advice, which only leads to Mrs Tishell shutting the pharmacy, inconveniencing everyone.