Kah-Lan is a young sea otter ready to leave the raft he grew up in. He sets off for adventure in an ocean filled with new sights and sounds and smells—among them humans and the sharp scent of fuel.

The ocean is a dangerous place for an otter on his own, and Kah-Lan must find other otters to raft with if he wants to survive.

Kah-Lan eventually makes new friends, two young male otters named Zid and Gula. After the three friends weather a storm together, they head off in search of new hunting waters. But the storm brought new dangers, and Kah-Lan and his friends soon find themselves on a mysterious and dangerous journey. Along the way, Kah-Lan discovers that help can be found in some very surprising places.