Lady in the Lake (movie, 1946)

Private detective Philip Marlowe is asked by a publishing executive, Adrienne Fromsett, to locate the wife of her boss, publisher Derace Kingsby. Earlier she had sent her husband a telegram saying she was heading to Mexico to marry Chris Lavery. However Kingsby had recently seen Lavery in the neighbouring Bay City. Marlowe pursues his investigation at the Kingsby's lakeside cottage.