Surprisingly, not the nadir of Chevy Chase's career but it might be close!  Steve Rash's Under the Rainbow, a fictionalized recounting of the little people actors from The Wizard of Oz taking over a hotel across from the MGM soundstages. Against this event is story of Arch Duke Franz Ferdinand's son being hunted by the son of Gavrilo Princip (Robert Donner). Fortunately, the Duke is protected by Bruce Thorpe (Chevy Chase), his intrepid guard.