Suppose you were locked into one of the most secure prisons in America at the turn of the twentieth century. You've been put into solitary confinement, with periodic inspections by the warden, whom you'd informed that you would escape in less than a week. How would you communicate with the outside, how would you smuggle in tools and weapons, and how would you finally break out? This was the situation confronting Professor Augustus S. F. X. Van Dusen, aka The Thinking Machine...Also in this volume: The Crystal Gazer; The Scarlet Thread; The Flaming Phantom; The Problem Of The Stolen Rubens; The Missing Necklace; The Phantom Motor; The Brown Coat; His Perfect Alibi; The Lost Radium; Kidnapped Baby Blake, Millionaire; The Fatal Cipher.