The Secret Fury (1950)

"The Stranger at her wedding was a messenger of Fear and Evil!"

The wedding of Ellen and David is halted by a stranger who insists that the bride is already married to someone else. Though the flabbergasted Ellen denies the charge, the interloper produces enough evidence that his accusation must be investigated. Ellen and David travel to the small coastal town where her first wedding allegedly occurred. There, they meet a number of individuals whose stories make Ellen question her own sanity.