The novel centers on the fate of its eponymous abbey and the characters contained within, although much of the book takes place in the forest surrounding the Abbey. Redwall Abbey was founded by an ancient female mouse named Germaine, and a great mouse hero named Martin the Warrior, who swore himself to peace after founding the abbey, and his followers throughout the ages have done the same. One of the abbey residents, Matthias, dreams more of times of adventure than a life of quiet servitude, but he is counseled to patience by his elders. Redwall is a fixture in the local community, set in the heart of Mossflower Woods, and was designed to be a place of refuge for the beasts of the forest in times of trouble.
Trouble arrives in the form of Cluny the Scourge, in the Summer of the Late Rose. Cluny is an evil, infamous rat, owning an extra-long tail with a poisoned barb on the end, and commander of a horde of vermin. He has only one eye, having lost the other in a battle with a pike. The foebeasts arrive at the beginning of the book and make their headquarters at the Church of St. Ninian, to the south of Redwall, with the intention of taking the Abbey for themselves. The Abbey inhabitants, who refuse to back down, make ready to defend themselves if necessary, especially since most of the inhabitants of the surrounding area are now within its walls. None of them are particularly martial, but Redwall folk, and indeed much of the Mossflower population, are generally described as slow to anger but fierce fighters when roused, and they are able to make an effective defense. Matthias, fearing that Cluny will still overrun them, begins a quest to find the legendary sword of Martin the Warrior, which is supposedly hidden somewhere within the Abbey, stored away for a time of need. He is helped particularly by Methuselah, an old and grizzled librarian mouse. Matthias is a brave-hearted young mouse, if small in stature, and as the story continues, his natural leadership abilities begin to emerge.
Clues to the location of Martin's sword, as well as his shield and the sword's scabbard, have been built into the Abbey. Matthias recovers the latter two, and with Methuselah's help eventually divines where the sword is hidden. Unfortunately, it isn't there any longer, having been stolen by a wild sparrow tribe that dwells on the Abbey roof and then by an adder (snake) named Asmodeus, who appears throughout the novel to pick off wandering creatures. After killing the crazed Sparrow King, Matthias continues to the lair of the gigantic snake Asmodeus, acquiring several allies: Log-a-Log, the leader of a local band of shrews; Basil Stag Hare, wandering do-gooder and general cad, and Warbeak Sparra, the aforementioned princess of the sparrow tribe. He also befriends Captain Snow, an owl, and Squire Julian Gingivere, a cat. Matthias and Log-a-Log succeed in retrieving the sword from Asmodeus's cave (in the process killing the snake) and Matthias rushes back to Redwall to save his friends after being tipped off by the sparrows about the fall of the abbey.
Cluny, in the meanwhile, has been attempting a number of unsuccessful strategies to gain entrance to the Abbey. He has had to deal with traitors such as Sela the vixen and her son Chickenhound, who kills Methusaleh, and had also been seriously injured from a fall. When all else fails, he captures a family of dormice and forces Plumpen, the head of that family, to open one of the gates or his family will be killed. Plumpen complies but he is knocked unconscious by Cluny. However, his victory is short-lived; soon after he takes over the Abbey, Matthias returns. Matthias, his new allies, and the assembled Redwall population turn on their captors; Matthias himself takes on Cluny, and defeats him by crushing him under the Abbey's bell, called the Joseph bell. However, a great deal of damage is done and there are many casualties. Abbot Mortimer, who was inflicted by Cluny's poisoned barb, dies after proclaiming Matthias Warrior of Redwall and Brother Alf the new Abbot of Redwall.
The novel closes with an epilogue. Matthias has married a fieldmouse named Cornflower and she has given birth to their son, Mattimeo, an abbreviated version of his full name: Matthias Methuselah Mortimer. Also, Brother Alf is now known as Abbot Mordalfus. John Churchmouse, a resident of the Abbey, is now the Abbey recorder.
source: Wikipedia
