In the kitchens of Redwall Abbey, Mattimeo, son of Matthias and Cornflower, fights Vitch, a mean little rat. Mattimeo is punished by his father for discourtesy to a guest. But Mattimeo's instincts about Vitch are validated when it transpires that Vitch is a spy for Slagar the fox - a slaver for the terrible underground Kingdom of Malkariss. Slagar gains entry to Redwall disguised as the leader of a troupe of magicians. At the great feast he is able to drug the drinks and capture Mattimeo and his friends: Tess, Tim, Sam Squirrel, and Cynthia Bankvole.
They join a group of slaves among whom is Auma, little daughter of Orlando the badger - who even now is hunting the fox. As the slaves are taken away, Slagar is revealed to be Chickenhound - the treacherous fox from season one - seeking revenge against Matthias the Warrior.