Passage: A famous cat pirate, Captain Nathaniel Joseph Claw, is imprisoned by the Cocker-Spaniards (a dog species, a pun on Cocker Spaniel) after they attack and sink his ship. In the prison cell, waiting for his execution, he finds a note and a piece of a map hidden in the wall. The note tells of the Amulet of Nine Lives—a mystical artifact that grants its wearer near-immortality. Breaking out of his cell, Claw sets out to collect all 9 gems of the amulet and retrieve it for himself.

Question: What did Captain Nathaniel found in the prison cell?
note and a piece of a map hidden in the wall