From bestselling authors Maggie Stiefvater and Jackson Pearce comes the third installment in a series bursting with magical creatures and whimsical adventures.

Pip and Tomas have dealt with magical creatures that burst into flames and runaway unicorns. Now they are headed with Tomas's family to Port Candor, a seaside showplace full of magical sea creatures. Soon they are surrounded by Slimekrakens and Tubafish and Spinnerseals and other dazzlers of the deep. And they are involved in a big mystery that involves a sea monster that might not be staying in its tank. The adults are confounded by the magical misbehavior—but Pip and Tomas aren't afraid to dive in!