Sidorio, fuelled by grief and revenge, is intent on becoming King of the Vampirates and building a new empire to bring terror to the oceans. He faces growing opposition from both the Pirate Federation, including Vampirate Assassin Cheng Li, and the Nocturnals - the more benign vampirate realm - led by Mosh Zu and Lorcan Furey. Both the pirates and the Nocturnals are forced to raise their game in response to the new and urgent threat from Sidorio and the renegade Vampirates. Twins Grace and Connor Tempest, still ricocheting from the recent discovery of their true parenthood and its explosive implications, are thrust deep into the heart of the conflict. Old foes and allies are thrown together in unexpected ways and, as the stakes rise higher than ever before, Grace and Connor find their alliances shifting in ways no-one could ever have possibly foreseen.