The Lone Wolf in London

In 1947, Inspector Garvey of Scotland Yard suspects Michael Lanyard, the reformed jewel thief known as the Lone Wolf, of the Eyes of the Nile theft. Lanyard denies involvement, claiming an alibi that he is in London with his butler Jamison writing a book and that he was in New York when the diamonds were stolen.

Lanyard and Jamison, short of funds, are invited by Ann Kelmscott to the Kelmscott family estate. They decide to go, hoping Sir John Kelmscott might offer a confidential loan or a path to better finances.

Sir John confides his desperate money needs and asks Lanyard to arrange a confidential loan using part of his jewel collection as collateral. Lanyard weighs the risk and the potential payoff as he considers the arrangement.

Jamison informs Lanyard that Lily the maid said Henry Robards is heartbroken because Iris Chatham has run off with Monty Beresford, who financed Iris's stage career. This adds a personal motive layer to the unfolding intrigue. Lanyard senses deeper entanglements around Iris.

Iris calls to invite Lanyard to the theater that night and asks him to stay away from the Kelmscott family. The request hints at Iris's involvement in the jewel plot and sets up a tense dynamic between them.

Lanyard decides to accept Kelmscott's offer and arranges to meet Bruce Tang, a gem dealer, the next morning to discuss terms. The meeting will determine whether the loan will be granted or the diamonds will change hands.

Kelmscott gives Robards a packet of jewels to deliver to Lanyard, but Robards steals the Eyes of the Nile for Iris. The theft immediately raises the stakes as the jewel goes missing and suspicion grows.

David Woolerton, Ann Kelmscott's fiancé, asks Lanyard for a ride because he wants to spy on him. This introduces an extra observer to the web of suspicion surrounding the theft.

At Bruce Tang's shop, Inspector Garvey has followed Lanyard; Robards' car stops and Robards is found dead behind the wheel, with the Eyes of the Nile missing. The pursuit intensifies as the trail goes cold and hot at once.

Woolerton claims Robards pushed him from the car and expresses suspicion that Lanyard murdered Robards. The accusation cements the danger surrounding Lanyard and escalates the manhunt.

Convinced Kelmscott is being blackmailed, Lanyard flees from the police and goes to Iris' apartment, where Monty and Iris scheme around the stolen diamonds. Tension rises as pursuers close in.

Lanyard and Monty struggle for control; Monty is subdued and Iris is prepared to flee with the Lone Wolf. The confrontation heightens the drama around the heist and the supposed mastermind.

In Iris's dressing room at the theatre, Lanyard discovers the diamonds sewn into her mink coat. Iris admits Robards had given her the diamonds, and Lanyard phones Jamison as Iris slips out through an open window toward the airport.

At the airport, Lanyard confronts Iris; Monty arrives with a gun and accuses Iris of planning the robbery and killing Robards. The confrontation exposes Iris's true involvement in the scheme.

Jamison brings Lily and Iris's mink; Lanyard extracts the Eyes of the Nile from the coat's lining, proving Iris was the thief and murderer. The mystery resolves as the true culprit is unmasked.