Roger Locke is a successful New York composer of stage musicals who decides to buy himself a farm in rural Connecticut as an investment. The farm house is decrepit and stands beside a stagnant lake. He decides to spend the night in his new home but awakens to find a woman in his bed beside him who holds a knife to him in the darkness. She warns him to leave the house and disappears. Locke leaves the house to his cousin and his wife to take care of it while he is in New York and when he returns next time, the lake by the house has grown wider and deeper. From then on he is visited by both the mysterious woman and an evil presence from the lake who claims that the woman belongs to him and vows that Locke will be destroyed.