Blueprint for a Massacre (, or Agente Z 55: Secreto atómico), also known as Agent Z-55: Atomic Secret, is a 1967 Italian-Spanish Eurospy film co-written and directed by Roberto Bianchi Montero and starring Germán Cobos.
The film was shot back to back with Desperate Mission, of which it is the sequel. During the shooting, Nick Nostro replaced Montero for two weeks.