When a prominent New York City banker is apparently murdered by the bite of a cobra, police inspector Harry Davis (Walter Fenner) contacts noted private detective Charlie Chan (Sidney Toler), who had previously tangled with a killer who used cobras as murder weapons. Arriving in Manhattan with his faithful son, Tommy (Benson Fong), and chauffeur, Birmingham Brown (Mantan Moreland), Chan is drawn into a complex scheme involving a secret government nuclear reserve being held at the victim's bank.