Bartholomew Cosmo -- eccentric inventor and millionaire -- is dead. His instructions to his lawyer, Pettibone, list his heirs and describe each. And he's left a condition to their inheritance -- they must spend the night in Cosmo Manor and discover the whereabouts of his most valuable possession -- the patent to the Cosmo Inflatable Neck Pillow. Audience members will fail in their attempts to impersonate the heirs. This is just as well, for when the lights go out, two people end up very dead. One is a family member -- the other a total stranger.