A woman and a man vying for a woman's affection: the usual love trio? Not quite so since the belle in question is Lorraine de Grissac, a very wealthy and alluring society woman, while one of the two rivals is none other than Arsène Lupin, the notorious jewel thief everybody thought dead, now living under the assumed name of René Farrand. As for the other suitor he is an American, a former F.B.I. sleuth turned private eye by the name of Steve Emerson. Steve not only suspects Farrand of being Lupin but when someone attempts to steal a precious emerald necklace from Lorraine's uncle, Count de Brissac, he is persuaded Lupin is the culprit. Is Emerson right or wrong? Which of the two men will win over Lorraine's heart?
as Rene Farrand aka Arsene Lupin
as Lorraine de Grissac
as Steve Emerson
as Count de Grissac
as Joe Doyle
as Georges Bouchet
as Alf
as Prefect of Police
as Duval
as Ivan Pavloff
as A. Le Marchand - Detective (as Ien Wulf)
as Monelle
as F.B.I. Special Agent
as Guard at Dock (uncredited)
as Detective (uncredited)
as Detective (uncredited)
as Party Guest (uncredited)
as Squad Car Driver (uncredited)
as Vasseur (uncredited)
as Hotel Assistant Manager (uncredited)
as Reporter (uncredited)
as Detective Alois (uncredited)
as François - Butler (uncredited)
as Woman Passenger at Dock (uncredited)
as Gendarme (uncredited)
as Man in Hotel Lobby (uncredited)
as André - Horse Groom (uncredited)
as Detective (uncredited)
as Truck Driver (uncredited)
as 'Butch' Harron - Gang Leader (uncredited)
as Telephone Operator (uncredited)
as Plainclothes Detective (uncredited)
as Fingerprint Man (uncredited)
as Bill Watkins - Criminologist (uncredited)
as Inspector Hennessey (uncredited)
as Switchboard Operator (uncredited)
as English Eddie (uncredited)
as Detective (uncredited)
as Party Guest (uncredited)
as Sergeant (uncredited)
as Man at Hotel Desk (uncredited)
as Hotel Manager (uncredited)
as Gendarme (uncredited)
as Reporter (uncredited)
as Gendarme (uncredited)
as Telephone Operator (uncredited)
as Burly Detective (uncredited)
as Man Leaving Hotel (uncredited)
as Reporter (uncredited)
as Gendarme (uncredited)
as Mr. Carter (uncredited)
as Radio Broadcaster (voice) (uncredited)
