Dateline: the day after tomorrow. Spectrum agents Captain Scarlet and Captain Black are assigned to investigate the source of unexplained extraterrestrial signals which have been detected emanating from Mars. They discover a strange and fantastic alien city but when their Bison Alien Terrain Vehicle is approached by a glowing green sphere, Black assumes that they are under attack and launches missiles which destroy the city. Miraculously, the city reforms and its alien occupants, the Mysterons, are disgusted by the violence of the Earthmen, pledging to crush their world. Black is apparently killed but Scarlet is returned to Earth as the Mysterons' instrument of destruction... Written by
Did You Know?
When Captain Scarlet is in the engineering room he knocks out the engineer but in later shots the engineer isn't anywhere in the room. The same thing happens again in later in the episode when Captain Scarlet knocks out a security guard after escaping from his cell but a few seconds later, when Captain Blue runs past the same area, the unconscious security guard is nowhere to be seen. See more
Earthmen, this is the voice of the Mysterons. We have watched you for centuries. Your violence disgusts us, and now you visit it upon us. You cannot destroy us, Earthmen, but now we will crush your world.