Troy's thirst for challenge and adventure is piqued when he stumbles upon large cat-like footprints in the woods near his home. But when his call to action isn't taken seriously, he has to convince his fellow mice of the impending danger.

The mice of his town, however, aren't prepared for the attack that ensues. Amid a forced retreat across the sea, negotiations with the rough and indiscriminate rats, and his own dishonesty and pride, Troy longs to be a good leader.

Along the way, he draws confidence and mentorship from an unlikely friend, and in the end he realizes the true nature of leadership. Will he overcome his own ideals and step up to meet the challenge ahead?