Scratch Kitten has just escaped from a landlocked life as the pet and plaything of some spoilt children. Determined to get back to sea, he tries to swim aboard a passing ship. When he doesn't make it, he is rescued by Jock, a deck hand on a tiny fishing ship bound for the North Sea in search of herring. Scratch should be in heaven but instead, he and Jock have their work cut out for them, trying to keep The Rat Pack away from their rat-phobic captain. Will Scratch and Jock get the better of these Terrible Beasties, or will it be the other way around...?