I signori di Marte

While Sigmund descends into the underground caves to look for Olga, the military personnel, who have discovered the Martian origin of the mutant beings, have formed a plan to retrieve their spores and destroy their nest. So an expedition is launched headed by Colonel Rotkopf, and its path is destined to cross with that of Nathan, Legs, May and Karen who have themselves come down into the caves in search of Sigmund and Olga. The expedition also bumps into Mike, who has by now been transformed and has escaped from the infirmary. The bottom of the caves seems to exert an inexplicable power of attraction over the Martian beings…