

A lab explosion doesn't just break glass—it shatters a man's mind. Who's really the monster here?
A chemist is left unhinged following a laboratory explosion and begins to plot a murder.
Acting
Frank Fox's twitchy descent from charm to unhinged menace.
Direction
Parker wrings genuine tension from a shoestring budget.
Production
Gaunt's cramped laboratory sets reek of authentic 1930s grime.
Director
Albert Parker
Trivia, insights & behind the scenes
Joan Hickson later became the definitive Miss Marple on BBC television, making her early role as suspicious servant Ellen a delightful bit of casting irony.
Released months before WWII, the film's atmosphere of creeping institutional collapse and individual breakdown eerily mirrors contemporary British anxieties.