Conspiring with Matthias, Constance builds a huge crossbow and shoots Cluny - but Cluny uses a substitute and escapes her arrow. Unknown to Redwall, he plans an attack with a huge movable siege tower. The abbey is saved when courageous Cornflower single handedly burns it down. Only then does the abbey realize Cluny is still alive and only Cornflower stood between them and disaster. Matthias and Cornflower become even closer warrior friends.

As Matthias is lost in Asmodeus' caverns, Cluny digs his way under Redwall, taking advantage of the exhausted citizens of Redwall. After using the sword to escape the caverns, Matthias and the shrews go on a terrifying river adventure and he returns with the shrews to defend Redwall - but not before he is almost trapped by Cluny and only just saved by Cornflower. Cluny flees at the sight of Martin the Warrior's "ghost" while Matthias at last gets to wear his hero's armor.

Cluny seizes the family of a dormouse and threatens to kill them unless their father, Plumpen, betrays Redwall and opens the gate to the now huge army of rats. The plan works and Redwall is finally captured. But Matthias challenges Cluny and in a final confrontation, he kills him. Cornflower and Matthias are at last married and Redwall returns to its idyllic lifestyle. Matthias has become like a hero he admired in his childhood.

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.

Redwall Abbey awakes to find their young ones are gone. As they piece the previous night together, they realized that Mattimeo was right that Vitch was the slaver's spy. Desperate that he ignored his son's warnings, Matthias vows to pursue Slagar the Fox accompanied by Basil and the others. He is unaware that Orlando is already in far away pursuit. Slagar takes his slaves on circuitous routes, laying false trails to confuse the pursuers. The frightened slaves look to Mattimeo for leadership but he is not ready and responds badly. As his father sets off in entirely the wrong direction Mattimeo learns the true story of Chickenhound - and that he is now a hostage to Chickenhounds who only thirst for revenge on Matthias for his mother's death.

In the kingdom of Malkariss, Matthias fights the slavemaster, Wearet, and falls into the abyss. There he grimly hangs on the rope that previously lowered a mysterious basket. But as Mattimeo and friends are released by the dying Log-a-Log, the Wearet cuts the rope and Matthias falls into the basket - and meets Malkariss himself! In Redwall, Stryk recovers slowly and becomes a close friend of Cornflower, but Ironbeak uncovers the 'hauntings' are a ruse and cunningly imprisons Constance as he prepares his final attack. The defenders are revealed and weakened - and Ironbeak is sure of victory. Matthias faces the evil, pale polecat Malkariss - whose slaves, seeing Matthias courage, turn on him and stone him to death. Matthias looks up to the high-above battle to see his son Mattimeo and fights to get to him. But he fails to see Slagar the Fox taking deadly aim at him with his bolas - and Slagar has never been known to miss.

In the pit of the kingdom of Malkariss, Matthias fights off Slagar who escapes to daylight as Matthias joins his battling friends - now reinforced by the released slaves. As Matthias joyfully embraces Mattimeo an earthquake shakes the ground. The terrible Polecat statue topples and with it the kingdom of Malkariss starts to collapse. At Redwall, Ironbeak penetrates the barricade which protects the citizens of Redwall and takes them hostage. He attacks Sister May which enrages huge Stryk who fights an aerial duel with Ironbeak, as Constance breaks free and attacks the birds from behind. Ironbeak's army swiftly surrenders and Redwall is saved! The kingdom of Malkariss is now doomed - but not before Matthias and Orlando are safely ejected from the earthquake, only to face Slagar, the cause of all their grief and loss. Fleeing from their ferocious attack he falls into the depths of the collapsing underground city.

As the Mirdrop threatens to destroy Martin and friends, Rose rushes the monster with a thick branch.

Martin and his friends are captured by Slo Worms and are dragged into the lizard's lair.

Martin tries to help the warden, who is under attack. He and his friends are then attacked by the Gawtrybe.

Brome and Felldoh attempt to get the slaves to safety when they learn Clogg and Badrang formed a truce.

Just as the Fur and Freedom Fighters arrive, Felldoh dies. The battle rages until Badrang offers a deal.

Martin and Rose confess their love for each other before tragedy strikes. Martin leads the troops to victory.

Matthias the mouse is orphaned when the vile rat Cluny the Scourge destroys his town. Adopted by the generous creatures of Redwall Abbey he grows up to admire their legendary protector, Martin the Warrior. But his peaceful young life is shattered when the Abbey is attacked by rats and Matthias meets their warlord - none other than Cluny! Matthias resolves to fight the tyrant that once again threatens his life - and his new family.

While Redwall prepares for a long siege, Cluny steals the symbolic tapestry of Martin the Warrior from within the abbey, and Matthias learns that Martin's great sword still exists - but nobody knows where. As Cluny's next attack is repulsed Matthias meets a new ally, Basil Stag Hare, and learns that his own destiny is inextricably linked to his hero Martin. Matthias will become Redwall's next protector - but only if his quest for the sword is successful.

Cluny uses two treacherous foxes, Sela the vixen and her son Chickenhound, to plant a false attack plan in Redwall, while Matthias and his mousemaid friend Cornflower unravel the mysterious motto, "I am that is." It is an anagram for "I Matthias" written years before he was born, another clue for the quest for Martin's sword. Cluny's real underground attack is inventively repulsed by hot porridge and Matthias sees the fearful snake Asmodeus for the first time and realizes that somehow their fates are horribly intertwined.

Following the complex clues which promise to lead to Martin's Sword, Matthias climbs high into the abbey roof - and the kingdom of the crazy King Bull Sparra. A feisty sparrow returns a kindness and addresses him as King Sparra flies to attack Asmodeus - who has Martin's Sword! The king returns in time to fight who narrowly escapes death. But at least Matthias knows where his sword quest must end in a battle against the vile snake!

A traveling circus comes to Redwall and Cluny uses it to try in infiltrate the abbey with his lieutenants, dressed as clowns. The mysterious circus star, Wild Ivy the Knifethrower, seemingly mesmerizes Matthias. But she is, in fact, an ally. As Cornflower is threatened with death by Cluny, Ivy turns her circus against the rats in an acrobatic battle of fire-eaters versus fur! And Wild Ivy has seen - that Matthias and Cornflower are destined to be together - if Redwall survives.

Cluny attempts to starve the abbey into submission as within Redwall pressure mounts as tempers flare. When Basil and Jess Squirrel seem to desert, Matthias wonders if surrender is close. He decided to try and rescue the stolen tapestry from Cluny in order to give courage to the citizens of Redwall - and discovers that Basil and Jess are attempting the same thing! They outwit Cluny, retrieve the precious tapestry of Martin, and renew the spirit of Redwall.

While Cluny plans to recapture the tapestry by burning down the abbey gates, Matthias determines to renew his search for Martin's sword but does not know where its keeper, Asmodeus, hides. He learns that only the fierce mouse-eating owl, Captain Snow, knows where he is. To ask him Matthias has to pass the gigantic marmalade cat, Squire Julian Gingivere, and the Shrew of Mossflower Wood! Matthias breaks off the search for the sword to return with his new allies to once again beat Cluny.

Cluny captures a traveling spice salesmouse an holds his wife ransom against the mouse entering Redwall and capturing Cornflower. Torn between love and honor, he does as Cluny demands. But with Matthias' help the two outwit Cluny with expansive flair and rescue the mousemaids, riding back to safety in a spectacular underground waterborne escape.

Matthias' wild sparrow friend, Warbeak, attempts to reconnoiter Cluny's camp as he prepares yet another attack on the abbey. She is captured and Matthias has to attempt to rescue her before Cluny feeds her to Asmodeus the snake. Posing as Cluny, Basil helps rescue Warbeak and Matthias sees Asmodeus once more and resolves to find a way to kill him. he stands between Matthias and Martin's sword and battle is inevitable.

Matthias sets off to find Asmodeus and recapture Martin's sword. Helped by the shrews of Mossflower he finally meets his foe in the deep caverns where he guards the warrior's sword - the object of Matthias' quest. In a terrible battle Matthias kills Asmodeus. At last the serpent is dead and the sword is his. Now he can truly be a protector of Redwall. But news of Cluny's assault reaches him and he realizes he is trapped deep underground.

Mattimeo realizes that the slaves are headed south while their parents are following false trails. They must escape by themselves or not at all. It is a slow beginning of his transformation as a leader, but not yet in time to save them from the treachery of Scurl the frilled newt who steals their few belongings for false freedom. Way behind the slaves, the Redwall pursuers meet Cheek, an alert orphan otter. In return for food and kindness, he sets them on the right track. He joins the hunt under the wry protection of Basil Stag Hare. The group encounters and joins forces with Orlando and a group of hedgehogs who have also lost a young one to Slagar. At Redwall Abbey Abbot Mordalfus dreams of Martin the Warrior who tells him to "seek the founder in the stones, where the little folk go." Constance, Cornflower, Formole and the others begin a task on deciphering the cryptic clue to the destination of Slagar, who moves southwards fast towards the dark mountain.

Mattimeo and the slaves make their first attempt to escape. Mattimeo takes another step towards his birthright of leadership. Matthias and the others are now chasing them in the right direction. At Redwall Abbey, Baby Rollo unravels the dream clue and the Redwall company follow the little folk - the ants - and so begin their own strange journey of pursuit which leads them to more cryptic clues. They struggle to solve something in the riddle that will help them help Matthias in pursuit of their young ones. The past and the present move towards a combined destiny - but what? As Mattimeo and the company hide from Slagar, Matthias and his companions approach the very gorge where Slagar secretly awaits them.