This study concerns the controversial case of Alger Hiss, who was suspected of spying for Soviet Military Intelligence. It does not concern his guilt or innocence but whether the U.S. Army Military Intelligence used an undercover spy-catcher to penetrate Hiss’s defense and to plant evidence forged to secure his perjury conviction. If so, Hiss’s conviction—which ushered in the McCarthy era and thrust Richard Nixon to national prominence—represents an alarming intrusion of our military into civil affairs.