Jack Sparrow and the crew of the Black Pearl come to a remote island looking for an artifact called the Cloak of Caladonis. The cloak is supposed to make the wearer invulnerable to physical attack, such as guns and swords. The Cloak hangs on a tree and is guarded by a four-headed serpent, the part of the story Jack forgets.
Once they come into contact with the serpent, they start to flee the area, but Jack boosts their morale and makes them fight harder. Meanwhile, Jack tries to cut the tree to render the serpent immobile. He is successful, but the serpent grabs the Cloak and there is no way to get it back.
After they board the ship, Jack reveals the branch is supposed to lead them to another, equally powerful, artifact.