Redwall slumbers in the summer sun, unaware that the mountain stronghold of Salamandastron lies besieged by the weasel army of Ferahgo the Assassin. Or that danger is creeping towards the Abbey in the form of the deadly Dryditch fever.

But when Mara the badger leaves Salamandastron, and the sword of Martin the Warrior sends Samkin and Arula from Redwall, the fates of the two strongholds becomes entwined through their dangerous and seemingly separate quests. Through forest and swamp and over great waters, Samkin, Mara, the ghostly white badger and a host of other brave creatures reach the same goal -- the final battle for Salamandastron!