As events in the Caribbean take place, Amy and Dan watch as the clue hunt kills a non-Cahill named Lester.

Angry and in shock, Amy and Dan decide to face Aunt Beatrice, but Nellie kidnaps them, and takes them to Moore Town to meet The Man In Black.

They are then forced to solve a puzzle box that Amy and Dan had found in the museum that Lester had worked at, finding slots that fit different items representing the branches: a jade with a dragon on it, a bear claw found in a cave, a wolf tooth on Isabel Kabra's bracelet, and the snake-shaped nose ring that Nellie wears.

After solving Anne Bonny's puzzle box, getting the Madrigal clue of Mace, and the knowledge that they should go to England, Dan and Amy learn that The Man In Black, who followed them in the first few books in the series, is Fiske Cahill, Grace's brother.

Hired by Grace, Nellie was spying for Fiske, so the branch would know about Amy and Dan in order to grant them a Madrigal status.