England, 1705: Framed for murder and on the run with her sisters, Nell Jackson turns her hand to highway robbery to survive. Aided by her superpowered sidekick, a plucky little sprite called Billy Blind, Nell realizes that fate has put her on the wrong side of the law for a reason. A reason much bigger than she could have ever imagined: to defeat a magical plot against the Queen of England.

London widow Cora Seaborne relocates to Essex to learn the truth about a rumored "sea dragon". When a local girl goes missing, fears escalate.

In the winter of 1820, the New England whaling ship Essex is assaulted by something no one could believe—a whale of mammoth size and will, and an almost human sense of vengeance.