Gaslight

The first film version of Patrick Hamilton's stage play about a Victorian criminal who tries to drive his wife mad in order to prevent her from discovering his guilty secret while he searches their house for a stash of precious rubies. Nothing like as lavish as the later MGM version with Charles Boyer and Ingrid Bergman, but in its own small-scale way a superior film by far. Lurking menace hangs in the air like a fog, the atmosphere is electric, and Wynyard suffers exquisitely as she struggles to keep dementia at bay. It's hardly surprising that MGM tried to destroy the negative of this version when they made their own five years later.