P.T. Mudd is a boy with an active imagination who loves to tell tall tales. But his wildest stories become reality when he discovers a magical stone that transports him to Muddlia, a land where he becomes the crown prince.

There's only one problem: everyone in Muddlia believes everything they're told. So, they naturally believe P.T. when he tells them that he is the greatest hero in the world, and they also trust him when he says that the Ultimate Evil of the Universe, Blotto Ratspaw, is putting together an army on the edge of their fair land.

Although the people of Muddlia have never known war, they follow P.T.'s advice to create their own army to save Muddlia from Ratspaw. Joined by new friends Chicki-Baby, a big blue talking chicken, and Belinda Bosh, a girl his own age who dreams of being a great champion, P.T. leads the trusting Muddlians off to war.

As P.T. boldly leads his loyal subjects, things begin to go terribly wrong. Unexpectedly, P.T. and his army are fighting against a very real, very nasty enemy. Now, P.T. must make an awful choice. Will he save the innocent Muddlians, or think only of himself and escape back to home and safety?