This volume features 13 novels and novelettes by Emile C. Tepperman, and his beloved character Secret Agent X, that appeared in the pulp magazine of that name.. Secret Agent X, whose true identity is never revealed, is a master of disguise, known as "the man of a thousand faces", and he adopts several different identities in each story. Although he is a dedicated crime-fighter working undercover for the U.S. government, this is unknown to the police who consider him an outlaw. His true role is known only to newspaper reporter Betty Dale and his mysterious Washington controller, K-9. The stories included in this volume are:I. TALONS OF TERRORII. CALL FROM HELLIII. CONSIDINE LAUGHSIV. THE EYES OF DURGAV. THE MURDER MONSTERVI. NO LIVING WITNESSVII. PAID IN SLUGSVIII. SATAN'S SCALPELIX. TOMB OF TORTUREX. TONG TORTUREXI. THE TERROR'S TRADE-MARKXII. TAKING NO CHANCESXIII. THE SUICIDE COTERIE