Things are not as they seem aboard the Diablo! There's a traitor aboard the ship and the Pirate Federation has been alerted of Captain Molucco Wrathe's law-breaking ways. Will the Captain be punished, and, more importantly, what will happen to twins Connor and Grace? Connor loves the life at sea, but Grace can't stop thinking of Lorcan and the friends she made aboard the Vampirates ship. To make matters worse, she also worries that with all of the risks Connor is taking, she may one day lose him. As Grace discovers, there is a place where Connor could learn more about the pirate way without risking his life: The Pirate Academy. And, as it happens, a good friend of theirs has connections at the selective school. In the end, Connor must choose between an education by sea or by school, and Grace has to decide if she's willing to follow.