Tom Stewart is a successful Jazz musician who has retreated to a small island where he intends to marry a girl named Meg Hubbard. However, trouble presents itself when Tom's old flame, Vi Mason shows up looking for him. Tom quickly takes Vi to the old lighthouse on the island. Tom explains that it's over between them, but Vi claims that she intends to blackmail Tom if she can't have him. However, as they go to the top of the lighthouse, the railing gives way, and Vi hangs from it, pleading for Tom to save her. However, he refuses to, and she plunges into the waters below.
The next day, Tom goes down to the beach, and sees Vi's body floating out on the water. Swimming out to it and returning it to the beach, Tom is shocked when it then turns to seaweed before his very eyes! Meg's little sister Sandy shows up shortly after wondering what Tom is doing. As he requests she leave, something in the sand catches her eye. It appears to be a watch inscribed with the name 'Vi.' Tom takes the watch from Sandy, and once she leaves, he throws it back into the ocean, claiming that's the end of Vi.
Tom returns to the lighthouse, where Meg eventually finds him. As they hug, Meg swears she smell perfume. Tom quickly ushers her out of the lighthouse down to the beach. However, as they talk, Tom swears he sees footprints in the sand following them. Meg sees nothing, and is surprised when Tom suggests they return to the main land to get married. Meg refuses to do so, claiming that this would upset her parents.
Tom then returns to his island apartment, but even there, strange things happen. A record player in the corner starts by itself, frightening him. The blind housekeeper Mrs Ellis stops by. As their conversation turns to talk of the supernatural, the old woman explains about a house she once rented that was said to still contain the spirit of a dead boy and his dog.
Tom soon after goes to sleep, but Vi even invades his dreams. Tom wakes in the evening, to see a light in the lighthouse. Going there and finding nothing, Tom declares to Vi that he is not going to live in fear of her, and that he will marry Meg.
The next day, Sandy visits Tom, who shows him the ring that he intends to give Meg. However, Tom soon sees the ring appear on Vi's disembodied hand. When he attempts to tell Sandy about it, she has no idea what he's talking about. Soon, the hand disappears, and after Sandy leaves, Tom demands the ring back, but gets no response.
Later on that evening, the family goes through several of the wedding gifts that have been received. Meg then decides to show Tom her gown, but is horrified to find the gown draped in wet seaweed, as well as a strange smell of sweet perfume in the air.
The next day, Tom is visited by Mrs Ellis who wishes to talk about what happened the night before. When Tom brings up word about Vi, claiming her to be an old girlfriend who he met and quarreled with, Mrs Ellis suggests that Vi may have planted the seaweed, playing tricks to get even. After she leaves, Mrs Ellis goes by the old lighthouse, where her seeing-eye dog starts barking at. Thinking Vi may be inside, Mrs Ellis enters. Vi attempts to lure the old woman up the stairs and over the broken railing, but Mrs Ellis manages to stop herself before going over.
Sometime afterwards, Meg's family is preparing for the pre-wedding party. Meg and Sandy's father arrives, and while he is happy to see his daughters and wife, he is still sour at the prospect of Meg marrying a jazz musician. Sandy later goes to the lighthouse looking for Tom, but is shocked when she comes across a man looking for Tom, and finds a pendant.
Shortly afterwards, the man finds Tom in his beach house. The man has come to the island looking for Vi, claiming she owed him 5 dollars for the boat trip over. The remembered Vi mentioning Tom's name, and thought he'd know where Vi is. Tom is tight-lipped about Vi, but pays the man the 5 dollars, trying to get him away. The ferry boat driver stops at a small cafe, and overhears someone talking about Tom marrying Meg, which gives him an idea.
Later that evening, a small pre-wedding party is hosted. Tom is freaked out when an instant photo shows Vi's head floating near him and Meg. When Meg notices Tom's nervous demeanor, Tom confesses to knowing Vi, and finally shows her the photo...only for Meg to see no floating head in the shot as Tom mentioned. This mention of Vi causes Meg to seem rather thoughtful later on during the night.
The next day, Tom attempts to practice at his piano, but is interrupted when Vi's disembodied head appears on a table. Vi claims that she will now use her voice to tell the world that Tom killed her. As she starts chanting 'Tom Stewart killed me,' Tom wraps her head in a towel and heads out the door, only to drop the head, which turns into a vase of flowers. He is the accosted by the same boat driver, who has found a locket of Vi's. When Tom attempts to take it, the man smiles, knowing he has information that Tom doesn't others to know about.
Tom and the ferryman go to the lighthouse, where the ferryman tells Tom he wants $5000 as payment to be kept quiet. Tom suddenly hears Vi's voice, pushing him to kill the ferryman, and Tom does so to keep his secrets. Unknown to Tom, Sandy was in the lighthouse, and secretly witnessed the killing.
The wedding is held and Vi's ghost shows up to open the door, wilt flowers, and turn the pages in the minister's book to the funeral service litany. Tom returns to the lighthouse after the failed wedding to see if Vi's ghost will appear. After seeing the light on, Sandy arrives and Tom realizes she saw him kill the ferryman. He lures her upstairs and is tempted to push her off the lighthouse, but Vi charges forward to push him off the ledge to the rocks below. Now a surprise waits when both Tom and Vi are recovered later.