In this thriller, Jonathan Fields (Bradford Dillman) awakens in a strange apartment and finds a dead woman floating in the bathtub after he suffered an LSD-flashback the night before. Finding blood upon his hand, he can only wonder how he is involved in the woman's death. He hires private detective Arthur Belding (Harry Guardino) who has him take another dose of LSD in order to see if he can remember what had happened. They learn that Fields' co-worker Lew Haley (Pat Hingle) had slipped acid into his coffee as part of a blackmail conspiracy. Haley was after his girlfriend and after his job in a government think tank. They also learn that his supervisor Dr. Arkroyd (Victor Jory) had been in a relationship with the deceased woman. She too was being blackmailed by Haley, who killed her when she threatened to call the cops. Dr. Arkroyd knew about it all and did nothing. Eventually Fields and Haley fight it out. The blackmailer ends up crashing through a high-rise window and falling to the unforgiving pavement below. Hope Lang, Susan Saint James, James Doohan and Michael J. Pollard also star in this psychedelic murder mystery.