The Crimson Stain Mystery is a 1916 American horror film serial directed by T. Hayes Hunter. 11 reels were found in the Dawson Film Find in 1978.

Plot

In this serial, Dr. Burton Montrose, a scientist, has developed a formula which he believes will make ordinary people into geniuses. He tests the drug on four subjects and, to his horror, finds that it turns them into compulsive criminals. The resulting band of thieves and murderers is led by the fiendish Pierre La Rue, known as the Crimson Stain for his luminous, red-rimmed eyes. He and his gang terrorize New York City, selecting wealthy victims as targets. They are pursued by Harold Stanley, editor of the Examiner newspaper, who has vowed vengeance for his father's murder. Aiding Stanley are his friend, Robert Clayton, his sweetheart, Dr. Montrose's daughter Florence, and a detective, Layton Parrish. Neither Florence nor anyone else knows the mysterious Crimson Stain to be none other than the doctor himself, driven insane by his own experiments.