Michael Keaton leads an all-star cast of Christopher Lloyd, Peter Boyle and Stephen Furst in this zany, high-energy comedy about four mental patients who get separated from their therapist on the way to a baseball game. Now it's up to Billy (Keaton), a pathological liar; Henry (Lloyd), an obsessive neat freak; Jack (Boyle), an ad exec with a messiah complex; and Albert (Furst), a reclusive coach potato, to save their missing doctor and lead the real maniacs to justice in this hilarious, unexpected adventure.