Brothers Ernie and Lars Smuntz have inherited a dilapidated old mansion. They don't give this event a special significance, because they consider it old junk. But what was their surprise when they become aware that their dilapidated estate is worth millions. But there is one problem. To sell the house, the brothers have to get rid of its stubborn occupant, a small, but very cunning mouse. What at first seems like child's play, over time, becomes a real, epic battle.