Two long-feuding kingdoms

Chubolia, a place where everyone is fat and Thinsylvania, a country where everyone is thin find themselves in the throes of battle when the prime minister of Thinsylvania, looking for someone to marry his prince, kidnaps the Chubolian princess.

But Hamilton Fatz, the charmingly romantic Chubolian captain of the guard, and Big Jim McBiggins, a roguish mountain man, are in love with her and vow to bring her home. But first they must cross the Belgies, an intimidating mountain range that separates the two countries.

The two men begin an incredible adventure to rescue her and must overcome physical and psychological obstacles along the way.