Harker Lee is a survivor. His mind withstands the threat of insanity and the pressure of imprisonment. His lifelong struggle to keep mind and body together in the face of the hostile environment of the maximum-security block is a struggle against the society of his fellow men. But that society can still find a need for him; a need for the ability to survive which it is testing to the full. He was taken from his cell once to be used in experiments in reading minds. Now he is brought forth again, to endure the ultimate test: to fly a Titan spaceship through hyperspace to the stars. Starflight destroys the minds of sane men. But Harker Lee is not sane and his mind has strength which sane men lack. In Harker Lee, the man whom society is caging for his crimes, now lies the hope that man might break out of the greatest of all cages: the void of empty darkness which enfolds the Earth. In this chilling, enthralling novel of psychology and science fiction, one final escape must be made, for a man and for mankind.