Obsessed with vengeance, Zydereen, the "Witch of Neptune," used her powers of mind control to force Dr. Zarkov (Joseph Nash) and Commander Richards (Henry Beckman) to destroy the civilisation on Neptune, a holocaust that (not surprisingly) only Flash and Dale can prevent. The episode starts off pretty well, as the supercilious villain mysteriously appears in the 'Galactic Bureau of Investigation' offices and takes over Zarkov's and Richards' minds. The story then drags a bit as we see repeated footage of panic on Neptune (including footage of Soviet crackdown in East Berlin - most of the series was shot in Germany) before Flash and Dale land on the threatened planet. There is then a lengthy sequence of Zydereen's henchman running to the backup oxygen plant (despite his boss having a matter-transmitter that could have put him anywhere on the planet) before being anticlimactically knocked out in a fist-fight with Flash. Steve Holland is hunky and heroic as the titular hero (he quickly dispenses with his shirt when working on the oxygenator) and Irene Champlin's Dale is refreshingly level-headed and competent for a pretty female 'sidekick'. The transition from the old 'Ming the Merciless' storylines to one in which Flash and Dale are agents for the world government likely reflects post-war politics and there is an interesting example of 'peace through strength' cold-war mentality: after initially denying the fact, Zarkov and Richards admit that they have the power to destroy the atmosphere plant on any planet in the solar system - a 'sword of Damocles' designed to prevent interplanetary war (as BGI can destroy any aggressors from Earth at the turn of a key). This episode is the first in a three-parter pitting Flash against Zydereen (Marie Powers) and is enjoyable in a retro-way (but don't expect 'scientific rigour' to get in the way of the story-lines).