Mattimeo by Brian Jacques
Mattimeo is a fantasy novel by Brian Jacques, published in 1989. It is the third book in the Redwall series.
Slagar the fox hates Redwall Abbey--its peaceable creatures, its fearless mouse warrior Matthias. And now, he is embarking on a terrible quest for vengeance, cunningly stealing away what the Redwallers most cherish: their young. And the greatest prize of all would be Matthias's headstrong son, Mattimeo.
