Dr. Burton Montrose, a famous scientist, discovers a biological element which he believes will improve the mental faculties of the human race. Instead, when tested on a few human subjects, the discovery reacts, turning them into cruel, bloodthirsty murderers. This band of arch-criminals is led by Pierre LaRue, a cunning leader, and they cover up their tracks so well that the only clue to their identity is the ante-mortem statement of one of the victims that the leader, known as the "Crimson Stain," has blood-red eyes. This book was transcribed from the newspaper novel written in 1916, and is being presented for the first time in book form as a companion to the new Blu-Ray restoration.