Paul Lavond was a respected banker in Paris when he was framed for robbery and murder by crooked associates and sent to Devil's Island. Years later, he escapes with a friend, a scientist who was working on a method to reduce humans to a height of mere inches (all for the good of humanity, of course). Lavond however is consumed with hatred for the men who betrayed him, and takes the scientist's methods back to Paris to exact painful revenge.
