Mr. Pin, the rockhopper penguin who has traveled from the South Pole to be a detective in Chicago, investigates two cases involving chocolate. Sequel to "The Mysterious Cases of Mr. Pin."

Mr Penguin is boarding a luxury cruise ship. He doesn't like water, and he can't swim, but his friend Colin is performing with the Ladies Choir on board - and anyway, Mr Penguin feels like a rest after some busy Adventuring. What's more, fish finger sandwiches are apparently available twenty-four hours a day. Heaven! But despite the glamorous film stars and party atmosphere, Mr Penguin can't help but feel that something shifty is happening on board....