Three weeks have passed since Cassandra Leung pledged her allegiance to ruthless pirate-queen Santa Elena and set free Bao, the sea monster Reckoner she'd been forced to train. The days as a pirate trainee are long and grueling, but it's not the physical pain that Cas dreads most. It's being forced to work with Swift, the pirate girl who broke her heart. But Cas has even bigger problems when she discovers Boa is not the only a monster swimming free....