Amnesia (1997)

Paul Keller is a married pastor who preaches piety on Sunday, while carrying on a torrid affair with the local school teacher, Veronica Dow, during the week. The lovers concoct a scheme to fake Keller's death so that they can be together, but the plan goes awry when Keller hits his head and awakens not knowing who he is. A dazed Keller wanders into the motel he used for his secret liaisons, and is found by Charlene Hunt, a lonely and desperate motel manager, who realizes Keller has amnesia and makes him her prisoner and lover. In the interim, Keller's wife Martha is suspected of foul play by an insurance investigator and forges an unwitting alliance with Dow, her husband's lover.