The Devil's Wheel (1918)

De Guise visits the Paris home of the Marquis Henry De Montfort to obtain the marquis' system of beating the roulette wheel. In the struggle, De Guise kills the marquis and then abducts his daughter Blanche, who has fainted. On the road, De Guise is knocked unconscious in a fight with the "Stag," a leader of the Paris underworld, and the latter takes Blanche to his den in the slums. Blanche awakens with no recollection of what has transpired and begins a new life with the Stag. Using her father's roulette system, the two soon make a fortune and enter Paris' select gambling society. Blanche meets De Guise, stabs him, and is arrested, but an operation for "pressure on the brain" saves her from prison and restores her memory. De Guise recovers and again abducts Blanche, but the Stag comes to her rescue and, now choosing straight life, finds happiness with her.