In a city not unaccustomed to murder as a daily staple of print and broadcast journalism, someone has found a new method of killing: a serial killer is terrorizing New York City with a series of brutal murders more apropos of the fourteenth century than the twentieth century. The killer is using caltraps-a medieval device for laming horses on a battlefield. The NYPD enlists the aid of Dr. Bradley Davison of Queens College, a noted authority on medieval...