Captain Barracuda is obsessed with finding Phineas Craneās treasure, the most valuable and sought after by all the pirates of the Caribbean. To achieve this, he will need the help of Sparks, a girl who pretends to be a boy in order to survive among the savage members of the Barracuda crew. Finding a Phineas Crane memoir will be the key to reaching the long-awaited treasure and also Sparksā lifeline, since she is the only one who can read on the ship and, therefore, the only one capable of deciphering that āLetter mapā that the found manuscript supposes.