Plot
Michael Lanyard (Bert Lytell), the famed reformed jewel thief known as The Lone Wolf, arrives in New York, where police, led by Inspector Ethier (Robert Elliott), are on high alert after cables from France warn of his approach. At the Duval Antique Auction Galleries, Lanyard casually outbids spirited society woman Helen Fairchild (Gertrude Olmstead) for a rare Chinese vase. The affront to her pride is compounded when Count Polinac (Charles K. Gerrard) tries to sell her a supposedly valuable Van Wirth painting, only for Lanyard to publicly reveal it as a fake—pointing out that tobacco was unknown in the painter’s country at the time. Both Helen and the Count are infuriated.
The scene shifts when a pendant once owned by Catherine the Great goes missing. Lanyard discreetly lifts it from the handbag of the elegant but duplicitous Countess Polinac (Lilyan Tashman) and plants it where the police will find it, exonerating himself and forcing a grudging apology from Ethier.
Now a self-proclaimed art collector for Herve of Paris, Lanyard’s real reason for being in America is to see Adrienne (Florence Allen), the adopted daughter of a late friend. Adrienne is in love with Bobby Crenshaw (Donald Keith), heir to a wealthy family, and Lanyard, approving of the match, excuses himself.
He soon makes a bold, unconventional call on Helen, entering through her window to deliver the Chinese vase, stealing a kiss as “payment” before vanishing again.
Later, Lanyard attends the Crenshaw estate’s engagement party for Adrienne and Bobby. Among the guests are the Polinacs and Helen. While Polinac searches Lanyard’s luggage, Lanyard reciprocates, finding a set of imitation pearls intended to replace Mrs. Crenshaw’s (Ruth Cherrington) genuine strand. Polinac sets a trap using the cover of a “Lone Wolf” warning to persuade the guests to lock their jewels in a safe. He then pressures Lanyard to open it, threatening to ruin Adrienne’s marriage prospects by revealing his identity. Lanyard agrees only to open the safe, refusing to touch the loot.
That night, Countess Polinac tries to seduce Lanyard into a partnership, only to be turned away—an exit witnessed by Helen, who becomes jealous. She later catches Lanyard apparently opening the safe, unaware that he is removing the jewels for safekeeping in a hidden location.
The Count’s attempt to steal the contents is foiled when the safe is empty. In the morning, imitation pearls are “found” in Lanyard’s room, leading to his arrest. While the Polinacs attempt to flee, they are brought back after a clever ruse in which Lanyard poses as the chauffeur.
As accusations fly, Scotland Yard telephotos reveal the Count and Countess as wanted international jewel thieves. Lanyard produces the real jewels from a file book where he had hidden them under each owner’s initial. Ethier clears him, and Helen—realizing her mistake—apologizes, sealing her newfound affection for the gallant rogue.
