When Nico rescues an octopus caught in a fisherman's net, his parents think it's a strange choice of pet. Nico keeps it in a tank, feeds it crabs and small fish and soon discovers that his octopus is extremely clever - amazing, amusing and always surprising. It can pull a cork from a bottle and drill a hole in a shell with its beak. But the worst thing in the world happens: Nico's octopus gets ill, and when his friend the old fisherman tells him why, it's sad news, but wonderful too...