A bunch of outlaws awaits the release from prison of an old goldminer, believed to have hidden 28 sacks of gold 20 years before... They all want the old man to speak, but only one of them will fulfill his dream.

An electronic ray that can counter any aerial attacks has just been invented by Professor Goodwin, but before he can put in good hands, he is kidnapped by a criminal organization, that starts an international bid for him and his invention among the rogue countries of the world. The CIA sends Agent Sigma 3 to find the Professor before the transaction takes place. His mission takes him from Rome to Tangiers, and to Barcelona.

Several murders have taken place in London. All the victims are prostitutes and the murderer is using the same techniques as Jack the Ripper. Peter Dockerman, an ex-acrobat and husband of one of the victims is the prime suspect. But whoever the killer is has cannibalistic tendencies and if Scotland Yard doesn't solve the murders quickly the evidence just might be eaten!