The Crowded Earth by Robert Bloch, Science Fiction, Fantasy, Adventure

THE WORLD GONE PSYCHO
Harry Collins is an ad-executive in a future Chicago on an Earth whose population has exploded beyond imagining. Crazed by the pressures of overcrowding, he seeks escape with a suicidal leap from a skyscraper. Stopped, he is hustled off for psychiatric treatment in a odd encampment where he meets an falls in love with an accommodating nurse named Sue. But who is the strange Dr. Leffingwell, performing experiments on the premises? Harry's horrific discoveries in the secret lab cause him to flee into the outside world -- flee into the forces that would help change and shape this tortured world. But then, years later, when his assassin's rifle is trained on Dr. Leffingwell himself, he is halted by the mutant product of that fateful lab. His own son. Here is an exciting work of science fiction by an acknowledged master of suspense and horror, Robert Bloch.