After someone places sugar cubes laced with LSD in his cup of coffee, Jonathan Fields regains consciousness, only to find a woman drowned in his bathtub and flecks of blood on his hands and clothes.

Suffering from amnesia, Fields can't think of anyplace else to turn, so he hires Arthur Belding, a private detective, to help him find out what happened.

Returning to work at a scientific think tank, Fields encounters a concerned woman who claims to be his sweetheart, Helen Atterbury, and a colleague who's been after his job, Lew Haley.

A hippie, Dill, and an accomplice kidnap Belding and attempt to drug him, but the detective escapes and recuperates with the help of Sarah, his girlfriend.

A fistfight ensues between Fields and Haley, resulting in the latter falling out a window to his death.