Pat Fairlie [Ray Milland] is out of the Navy and travels to Jamaica to renew acquaintance with Ena Dacey [Arlene Dahl], an old flame from his past. Ena lives on a stately sugar plantation with her brother, Todd Dacey [Wendell Corey], and their mother, a family surrounded by pride and a veneer of wealth. The land, however, hides financial troubles that the Daceys mask with a nominal rent of one pound per year—an arrangement born from a long-ago bargain after documents proving the rightful owner’s purchase vanished at sea.
Montague [Patric Knowles], a sharp-eyed land baron, arrives to collect the rent and ends up proposing a more ambitious plan. He believes the chest that supposedly contains the vital documents can be recovered from the ocean floor and wants Pat to be the diver. Janice Clayton [Kasey Rogers] shares claim to the property with Robert Clayton, pushing for a legal resolution in Montague’s favor. Pat refuses at first, but Montague explains that some other diver will take the job, so Pat might as well be present to watch over Ena’s family interests.
Soon, mysterious events begin to unsettle the island. Todd’s affections seem to deepen for Janice, yet when she nearly drowns and Pat pulls her from danger, Todd’s behavior grows suspicious. The situation escalates when Robert Clayton is found dead on the ocean floor, and Inspector Mole [Murray Matheson] arrives to investigate. The inspector quickly concludes that the death is a murder, not an accident, adding pressure to a case already tangled with factional claims and buried documents.
A treasure chest is surfaced, seemingly containing the documents that could settle everything, but the tension thickens as an attempt is made on Pat’s life. Pat and Ena decide to take matters into their own hands, quietly investigating and following leads. Their quest leads them to an antique dealer who recently sold such a chest to a buyer, a detail that begins to unravel the web of deceit surrounding the property and its rightful ownership.
As the clues mount, Montague is exposed as the culprit behind a calculated land swindle built on forged documents. His arrest for Robert’s murder closes one chapter of the plot, but the danger isn’t over. The plantation’s future hangs in the balance as Mrs. Dacey, driven by fear and instability, sets fire to the plantation, forcing everyone to act quickly to save what remains.
In the end, the true motive behind the whole affair is laid bare: a desire to control land and wealth under the guise of legal rights, with Pat and Ena’s alliance offering a path to resolve the conflict and protect the family’s legacy. The case closes with justice served for the murdered Robert and a race against time to salvage the plantation from its fiery fate.
