With her Pokémon-obsessed children in tow, Jenn rents a summer house on Pearl Island. But shortly after she arrives, a boy emerges from the nighttime sea. His name, he says, is Timmy Caruso. He’s ten years old. And he’s on mission to save the world.

In the days that follow, Jenn grapples with work deadlines, her own spirited children, the mysterious boy from the sea, and her burgeoning interest in a very sexy contractor. But when alarming events unfold along the coast—shark attacks, tidal waves, a proliferation of sugar-addicted sea creatures, and a terror out in the deeper water—she wonders if, just maybe, the young boy knows what he’s doing after all.