John Marquez

A new police officer, who has narcolepsy, replaces Mark Mylow; Martin treats a girl who's been taking her mother's diet pills.

Louisa ends her relationship with Martin, but when she needs him to treat her injured friend, he gets a chance to redeem himself.

It's Doc Martin's last day in Portwenn, and his office is packed with patients. Edith turns up, expecting an apology, and Aunt Joan rebukes Martin as well. Louisa is in a car accident that causes Martin to doubt his decision.

Louisa Glasson finds out she has a rival for Doc Martin's affections; Martin accidentally runs over a dog.

Unhappy with his lot in life, Bert Large abandons his plumbing business to start his own restaurant, but the eatery's opening is followed immediately by several cases of food poisoning.

Louisa's new neighbors cause problems for her, for Martin and for other residents; townspeople notice something unusual about Joe Penhale.