An American, Chris Smith, wakes up in an English hospital unable to remember anything of his life before a recent car accident.
Four months later he has recovered physically but has still not retrieved his memory. His amnesia is being treated by a psychiatrist, Dr. Keller, who tells him that his bills are being paid by an anonymous benefactor, who has made an apartment available to him. Dr Keller warns him that he might suffer hallucinations.
The only other link to his past is a photograph torn from a newspaper. Chris has fallen in love with his nurse, Gina.
Upon release from the hospital, Chris moves into a flat and hires a private investigator, Hemmings. Chris visits the photographer of the photo, who tells him that the subject is dead, the victim of a shower murder.
In his flat Chris hears strange voices coming from next door - a couple arguing. He keeps seeing a woman around town, from time to time, who reminds him of the woman in the photo. And he discovers a bloody knife in his shower.
Chris receives a late night visit from Denise, who claims to be the widow of the man responsible for the automobile accident which caused Chris to lose his memory. Denise bears a remarkable resemblance to the woman in the photograph.
Denise plies Chris with drugs, and after one such episode, he discovers in his shower the body of a murdered woman, which later disappears.
Assisted by Hemmings, Chris tricks Denise and Keller into admitting that they are the murderers, having planned to frame him for the crime, and that the victim is the physician's wife. Chris is reunited with Gina.Robert Webber as Chris Smith
Anthony Newlands as Dr. Keller
Jennifer Jayne as Gina McConnell
Maurice Denham as Hemmings
Lelia Goldoni as Denise James
Peter Woodthorpe as Marcus Allan
Sandra Boize as English Girl
Sue Lloyd as French Girl
John Arnatt as Mr. James
Marianne Stone as Marcus Allan's Secretary - Miss Grogan
Irene Richmond as Mrs. Keller
Kiwi Kingston as French Girl's Husband
The film performed disappointingly at the box office.
James Carreras of Hammer announced they had a film called Brainstorm to follow Hysteria but this appears to have not been made.
Hysteria was released to DVD by Warner Home Video on November 2, 2011 via the Warner Archive DVD-on-demand service as a Region 0 widescreen DVD.