French public prosecutor Pierre Donnay is almost killed when attempting to capture France’s most elusive and diabolical criminal, a notorious kidnapper and murderer who wears a mask to cover his hideously disfigured face.

Donnay’s life-threatening injuries put him into a hospital in a coma for a lengthy stay, and later into a sanatorium for an even lengthier rehabilitation. Released at last in good health eleven years later in 1920, Donnay returns to the Palace of Justice to resume his old position but a devious former underling now in a position of power says there are no openings. Donnay is relegated to working in the basement archive sorting old police files. There, he comes upon significant background on the allegedly deceased criminal he’d been chasing – real name Arik Cassell, a former carnival performer and drug-runner for the Corsican mob.

Donnay unearths more facts that lead him to believe Cassell may still be alive and has fled the continent some time ago for America – to a place called Hollywood. Donnay heads there to expose him.

Calling himself Sebastian Vane, Cassell has attained success in pictures as a “man of mystery” not unlike his only competition in that category, the equally popular Lon Chaney. Cassell uses the charade to further his drug-importing activities without suspicion. When Universal Pictures announces it will make a big-budget film of the bestseller loosely based on the “deceased” criminal’s notorious life starring Lon Chaney, Cassell/Vane goes berserk and acts to shut the production down.