Inspired by the eccentric, reclusive Wendel Family of New York's Fifth Avenue, Elizabeth MacFadden's stage melodrama Double Door was adapted for the screen in 1934. Set in 1910 Manhattan, the film stars Mary Morris and Anne Revere, repeating their stage roles as domineering, calculating Victoria Van Brett and her weakling sister Caroline. The title refers to the door guarding the Van Brett's secret vault, wherein are stored the family jewels. Years earlier, Victoria, the only member of the family who knows the vault's combination, locked Caroline in the dark, airless chamber, literally frightening her into madness. At present, the misleadingly sweet-natured Victoria has embarked upon a campaign to destroy Ann Darrow (Elizabeth Allan), the new bride of her half-brother Rip Van Brett (Kent Taylor). When her efforts to accuse the girl of having an affair with doctor John Lucas (Colin Tapley) fail, Victoria does her utmost to lure Ann into the vault, intending to lock her in and drive her insane. Perhaps it goes without saying that the heroine will survive, and that Victoria herself will be forever entombed behind that double door.