249, [3] pp. From the jacket flap: "One of the strangest, cleverest and most ruthless of all criminals was this man who worked behind the disguise of the Rubber Mask. His face, a blank, flabby, shapeless thing, im;possible to recognize or identify; his brain, keen, resourceful, vengeful; his body, strong, agile, of tremendous endurance. This was the enemy against whom young Bob Swenson undertook to match his wits and physical strength. The odds were all against Swenson, for the Rubber Mask - as the criminal was known - was an expert in crime, while Swenson was little more than an amateur detective. His only hope lay in the old adage that even the cleverest scoundrel is likely to make one fatal mistake. This is a detective story packed from cover to cover with exciting incidents, as Bob Swenson carries on his relentless fight to bring the Rubber Mask to the end of his trail."
