When the Pirate Federation and Nocturnals form an alliance to battle the renegade Vampirates, twins Connor and Grace Tempest each have important roles to play in the war--he as a pirate warrior and she as a powerful healer working with the war-wounded.
A rival ship of Vampirates creates unwanted competition on the seas and Captain Li goes on the hunt with Connor Tempest; meanwhile, Connor's twin sister Grace spends some valuable time with their mother and learns their family's shocking history.
Evil Sidorio continues to expand his empire across the oceans, but as he faces growing opposition from both the Pirate Federation and the vampirate realm, twins Grace and Connor Tempest are caught in the conflict.
While Connor faces trouble in the form of an obnoxious new crewmate, Grace, his twin sister, seeks out a vampirate guru who might be able to heal their dear friend Lorcan's blindness.