A mysterious martial artist is killing martial arts masters with his unique style, Tiger Claw. Two police detectives, who are also martial arts experts, use unorthodox methods to track down the serial killer.

Seen-it-all New York detective Frank Keller is unsettled - he has done twenty years on the force and could retire, and he hasn't come to terms with his wife leaving him for a colleague. Joining up with an officer from another part of town to investigate a series of murders linked by the lonely hearts columns he finds he is getting seriously and possibly dangerously involved with Helen, one of the main suspects.