Mike is a tad delusional. Harry believes he's a doctor. Jack is an ad executive who believes Jesus is speaking to him. Albert is an adult who occasionally wets himself. When they are taken to a ball game by Dr. Weitzman they witness a murder and Weitzman is attacked and hospitalized. The four crazies find that Weitzman will be murdered as a witness and no one believes four mental patients. They have to both use and overcome their delusions in order to save the only decent doctor who is treating them, with both the police and the killers looking for them.
Michael Keaton ... Billy Caufield
Christopher Lloyd ... Henry Sikorsky
Peter Boyle ... Jack McDermott
Stephen Furst ... Albert Ianuzzi
Dennis Boutsikaris ... Dr. Weitzman
Lorraine Bracco ... Riley