When the evil worm lord Sebaceous Ooze uses his magical song to enslave mice to dig a volcano that will help him and his slobber goblin armies take over the world, it's up to Amber, a mouse with magical powers, to stop him. With her devoted friends by her side - Ben, a mouse who used to be a human boy; Thorn a genius mouse; and Bushmaster, the wise vole - Amber might stand a chance of thwarting the giant worm's sinister plan. But with a human army...