Young mouse Calib Christopher dreams of the day when he will become a Knight of Camelot like his father and grandfather before him. For generations, Calib’s family has lived among the mice that dwell beneath the human Knights of the Round Table, defending the castle they all call home. Calib just hopes he will be able to live up to the Christopher name.

Then, on the night of the annual Harvest Tournament, tragedy strikes. The mice suspect the Darklings are behind the vicious sneak attack, but Calib has his doubts, so he sets off on a quest for the truth. Venturing deep into the woods beyond the castle walls, Calib and his friend Cecily discover that a threat far greater than the Darklings is gathering, and human and animal knights alike are in grave danger.

With help from a host of unlikely new allies, including a young human boy named Galahad, Calib must get the Mice of the Round Table and the Darklings to put aside their differences and fight together. Only then will they be strong enough to save Camelot.