Caught in the depths of their strange new world, Mo' Steel and Billy Weir encounter a lost Remnant, Kubric DiSalvo. Unfortunately, the ship has transformed him, replacing his skin with a transparent plastic coating. Scared and awed by the ship's vicious power, the group tries to rejoin heir friends. Meanwhile, the other Remnants are in danger in another stratum of the ship: Yago and Jobs are stuck in a computer-generated sea battle. When the groups meet, Billy finds he can communicate with the ship's core. Will his strange past help him to understand or even control the ship in time to save everyone?
While Jake and the other Animorphs try to stop Visser Three from reaching the Pemalite ship at the bottom of the ocean, they discover a strange underwater civilization.