Schwab has committed a hideous crime. He knows neither how nor why he did it. But he does know that he had no control over the lethal, telepathic power suddenly thrust upon him. Some unseen hand directed his actions. Facing the ultimate penalty for his deed, his one hope rests on reaching a planet light-years removed from his prison cell. There, in the underground tunnels of primitive Paria, lies a clue that could lead him to the unknown lunatic whose tool he has been.