Sylver and his band of weasels take to the high seas in search of the humans who mysteriously deserted the land of Welkin many years ago. On their tail is a very seasick Sheriff Falshed, commanded by the stoat rulers to stop Sylver at any cost. And if that's not bad enough, behind him is a ship crammed to the gunwales with bloodthirsty rats, convinced that Sylver is secretly hunting a pirate's treasure.