Sam Higgins alights at the train station for the Welsh village of Tan-Y-Bwlch to take over the North Stack lighthouse, which is believed by the locals to be haunted. There, he meets Alice Bright. She asks him to take her along to the lighthouse, explaining that she belongs to a "psychic society" and wants to investigate the "legend of the phantom lighthouse". He turns her down.
Sam reports to Harbour Master David Owen, who informs him that Jack Davis, Sam's predecessor, "just disappeared", as did the chief lighthouse keeper before him. Owen confirms there was a major shipwreck a year ago, caused, so he believes, by the phantom light. Jim Pearce tries to bribe Sam to take him to the lighthouse; Sam guesses he is a reporter. Alice later overhears Jim ask about hiring a boat, so she tries her charms on him, but again fails.
When Owen, Dr. Carey and others take Sam by boat to the lighthouse, Carey examines Tom Evans, a mentally disturbed member of the resident staff. Evans tries to strangle the doctor, who decides he cannot be moved in his present state, to Sam's discomfort. Just to be safe, Sam ties Tom up. Sam's remaining assistants are Claff Owen (David's brother and Tom's uncle) and Bob Peters.
Then Jim shows up in a boat that is conveniently out of petrol. To Jim's surprise, he has a stowaway: Alice. Sam starts questioning his unwanted guests. Alice now tells him she is "an actress hiding from the police" because two admirers fought over her with knives.
Strange things start occurring. First a fire breaks out near Tom's bed. Then, Sam overhears Jim plotting something with Alice and admitting he is not a reporter. He fears they may be communist saboteurs. Jim has Alice hang a radio aerial out the window of the bunk room, but Tom (whom Claff has untied) sees her do it and sneaks up behind her. Fortunately, he hears Jim returning, so he hastily retreats to his bunk. When Sam shows up, Jim tells him he is a naval officer after wreckers out to sink the Mary Fern for the insurance, most of the shares being held by the locals. Then Alice informs him that she is a detective from Scotland Yard.
Jim starts to transmit a warning to the approaching ship, but Bob and Claff are rendered unconscious, the light is sabotaged, and a decoy light is turned on. After Jim sends Alice to fetch Sam, Tom knocks Jim out and disables his radio. When Alice and Sam return, Tom locks them all in. Jim, however, climbs down the side of the lighthouse and swims to the village to alert the coast guard. Claff wakes up and unlocks the door, allowing Sam to set about repairing the light. They overhear Carey talking to Tom and learn that the doctor is the mastermind. The Mary Fern is saved just in time. Then, trapped at the top of the lighthouse, Carey decides to jump.Binnie Hale as Alice Bright
Gordon Harker as Sam Higgins
Donald Calthrop as David Owen
Milton Rosmer as Dr. Carey
Ian Hunter as Jim Pearce
Herbert Lomas as Claff Owen
Reginald Tate as Tom Evans
Barry O'Neill as Capt. Pearce
Mickey Brantford as Bob Peters
Alice O'Day as Mrs. Owen
Fewlass Llewellyn as Griffith Owen
Edgar K. Bruce as Sergt. Owen
Louie Emery as Station Mistress
The opening scenes were filmed at Tan y Bwlch station on the Festiniog Railway. The station is actually 7.5 miles from the coast.
Writing for The Spectator, Graham Greene described the film as "an exciting, simple story" and compared its plot to that of Gibson's "Flannan Isle". Specific praise was given to actors Harker (for a "sure-fire Cockney performance") and Calthrop (whom Greene favorably compared to Charles Laughton).
The film has been released on Region 1 DVD by MPI along with Red Ensign (1934) and The Upturned Glass (1947).
The film has been released on Region 2 DVD by Opening in the "Les films de ma vie" series. The DVD has non-removable French subtitles for the original English soundtrack.