Martin is in London to meet with Robert Dashwood, who is leading the selection process for the prestigious London surgeon's job that Martin has applied for.

Robert can tell that Martin is excited to be back in the world of surgery, and is pleased that Martin has finally conquered his debilitating haemophobia. Robert is confident that Martin will get the job.

On the train back to Cornwall, Martin is annoyed to be seated next to one of his patients, a sheep farmer named Jim Selkirk. Jim is a noisy eater, and when he falls asleep, he slumps on to Martin's shoulder. But when Martin tries to rouse him, he discovers that Jim has died of heart failure.

On his arrival in Portwenn, Martin is immediately summoned to Aunt Joan's farm. Louisa has taken some schoolchildren there on an educational trip, but one of the boys, Theo Wenn, has been naughty behind her back, and Aunt Joan has punished him by locking him inside the chicken coop. The boy, Theo, is having a panic attack.

In his Surgery, Martin is visited by Jim's widow, Mrs Selkirk. She is looking for emotional comfort, but Martin is not the person to provide it.

When Theo falls ill in Louisa's class, and is taken home, Theo's parents - Juliet and Richard Wenn - are certain that their child picked up the illness in Joan's chicken coop, and Martin cannot deny it is a possibility. The Wenns announce their intention to sue Aunt Joan.

Despite what he allowed Robert to think, Martin has not fully conquered his blood phobia, and he must visit Dr Milligan, a highly-rated cognitive behavioural therapist recommended by Edith. The session does not go according to plan, but Dr Milligan is charm personified, even when Martin walks out.

Mrs Selkirk returns to Martin's Surgery, and tells him she is now seeing visions of her dead husband. Martin orders her to get some rest.

Joan receives a threatening letter from the Wenns' solicitor and, on top of all her other financial difficulties with the farm, it causes her to collapse. Martin attends, but once he has left, Joan hurries to the Wenns' home to try and make things right. The Wenns are unsympathetic, and Joan - on the spur of the moment - lies to them about Theo's medical test results clearing her of any responsibility for his illness. Martin is furious with Joan when he discovers she has lied.

Martin receives a CD recording by Dr Milligan to help overcome his phobia.

When Mrs Selkirk is found collapsed in her sheep pen, Martin is able to uncover the medical reason behind her hallucinations, and when he receives Theo's test results, they do point to Joan's innocence and Martin is finally able to identify the real source of Theo's sickness.