1958. Cookbook writer and no-nonsense television personality Mary Mackerel must leave London in a hurry when public affection for her curdles. She reluctantly takes her publisher's advice to retire to the English countryside and write a cookbook that will reestablish her reputation. And so, she finds herself at the edge of the world: Penzance, Cornwall. The move also affords her an enticing opportunity when she buys a run-down tea shoppe with hopes of turning it into a bakery and restaurant. To ingratiate herself with the locals, Mary bakes Cornish pasties and gives the tasty treats away. After one of the locals dies of poisoning moments afterwards, the whole town points the finger at Mary as a murderer and the press gleefully pick up on the story. Mary must turn chef-detective, a role too reminiscent of her secret life during the war, to clear her name and save her fledgling business.