The wealthy Ashby family grieves the tragedy of the death of the patriarch and matriarch Ashby in an airplane crash and their son Tony, who committed suicide, eleven years ago. Tony jumped off the cliff and his body was never found, only a suicide letter. Presently the dysfunctional Ashby family in composed by the alcoholic and reckless organist Simon Ashby (Oliver Reed); his unbalanced sister Eleanor (Janette Scott); and their overprotective aunt Harriet (Sheila Burrell) and their finances are managed by the accountant John Kossett (Maurice Denham), who tries to keep SImon under control. A couple of weeks before the due date for Simon receiving his inheritance, Tony Ashby (Alexander Davion) surprisingly appears for the joy of Eleanor, but Simon and Harriet believe he is an impostor despite his knowledge about the family.

“Paranoiac” is an intriguing and suspenseful film by Hammer, with great storyline and deceptive conclusion. The screenplay builds tension and mystery with the viewer questioning whether tony is who he says. But unfortunately the rushed and senseless conclusion disappoints.