Crime is like disease. It strikes when you least expect it, and it's no respecter of persons or classes. It spreads in contagious ways. Most of the dangerous malady's of the past have been knocked out with medical advances and vaccines, but the only inoculation against a confirmed criminal, is a strong fist and a fast trigger - especially when you're up against a murder. Today the Fat Man is investigating a killing in a Greenwich Village apartment house, and a crazy old lady with a ball of string and a knife.