On a moonless night, two rats follow hypnotic lights into the forest, never to be seen again. Such is the power of the Doomwytes, sinister ravens led by the deadly Korvus Skurr.

When the young mouse Bisky persuades the creatures of Redwall Abbey to go in search of a fabled treasure, hidden long ago by one of the abbey's most notorious thieves, they do not suspect Skurr and his ravens will be vying for that very treasure.

Bisky and his fellow Redwallers must summon all their courage to face the evil horde of slithering snakes and vicious ravens. From underground tunnels to the tops of trees, the fearless Redwallers, with the help of their woodland friends, battle some of their most vicious enemies yet in an exhilarating, terrifying treasure hunt.

It has been four seasons since Mariel, the warrior-mouse daughter of Joseph the Bellmaker, and her companion, Dandin, set off from Redwall to fight evil in Mossflower. Nothing has been heard of them since.

Then one night, in a dream, the legendary Martin the Warrior comes to the Bellmaker with a mysterious message. Clearly, Mariel and Dandin are in grave danger. Joseph and four Redwallers set off at once to aid them. As they push over land and sea, they cannot know the terrible threats they face.

Will the Bellmaker and his companions arrive in time to help Mariel and Dandin?