Pertice McIlveen, a young Ontario woman who loves Hemingway and hates hats, receives a mysterious key in the mail. Accompanied by her best friend Es, she travels to Gannet Island off the coast of New Brunswick to find the door it fits into. There she discovers a charming cottage by the sea has been willed to her by a secret benefactor identified only as PM, on the condition she wears the hats that come with it. She accepts the challenge, leaving...