"DO YOU RELIZE THE DANGER YOU ARE IN?"

A wealthy young criminologist Marcel Leviget is seen forcibly dragging his fellow clubman Dr. Rogers into a House of Ill Repute. In one of the back bedrooms of the bawdy house, an old friend of Marcel's, a prominent attorney, lies near death. Dr. Rogers is also acquainted with the dying attorney, and while Marcel's back is turned, Rogers discovers a distinctively designed hatpin embedded in the patient's heart.