And No One Could Save Her (movie, 1973)

The life of young newlywed, Fern O'Neil, is turned upside-down when her husband is called home to visit his dying father in Ireland. When she fails to receive a phone call from her husband, she contacts the airline and discovers he was not on the plane. Further investigation reveals that her husband is not who she thought he was. Her search ultimately takes her all the way to Ireland, where her sanity and, of course, her story come into question.