“Devil’s Planet” is episode twenty-two of season two of Space: 1999.
Commander Koenig and Blake Maine from the medical rescue team are taking Eagle 1 on a recon mission to two planets that might support life. In orbit around one, they detect vegetation but no other life. A city is seen, however, with what might be people. There’s also a breathable atmosphere.
Blaine reports a lifeform reading in a clearing outside the city. They land, and he reports the signal has cut out. They find a cabinet with windows in the clearing, as well as the bodies of men and women. Maine can find no injuries. Back in Command Centre, Dr Spencer wants a close up. He guesses a bacteria or pathogen has killed them.
The box starts to glow and a man appears inside it. He steps out and Dr Spencer warns them to keep back; the man might be contagious. He tells them to get off the planet as the newly-arrived man collapses and dies.
The Eagle lifts off and Koenig reports back to Alpha that everyone is dead. Dr Spencer postulates they may have immunity. Before Eagle 1 returns, they decide to examine the satellite. It, too, has a breathable atmosphere and vegetation. However, systems fail on the Eagle and Koenig reports that they’re out of control before the signal is lost. Fraser wants their last know position, and heads to take another Eagle, with Alibe, after them.
Eagle 1 crash-lands and they flee the crash. They hear a strange sound, and there’s a man running. He’s dressed the same as the corpses on the other planet and is being pursued by three differently-attired women with some kind of whip. They catch the man before he can reach a metal obelisk. Koenig and Maine try to intervene, but Maine runs into an energy field that reduces him to a pile of smoking clothes and Koenig is caught when he’s distracted.
Inside a building, a man, Crael, is espousing the principal of freedom of speech regarding what another man is accused of. It seems the people in grey are prisoners and the women in red are guards. Elizia, who appears to be the leader, claims the other prisoner was inciting insurrection, and as long as she is the ruling authority on the penal planet, freedom of speech will not be abused by anyone.
Elizia is brought the commander’s weapon and told that he is with the Interrogator and that the prisoner almost made it to the sanctuary column. Elizia uses Koenig’s gun to shoot the prisoner Crael was defending. She’s told he’s stunned, not dead. Elizia wants him to go on the hunt. Crael says it’s inhuman. Not the chance to go home, but because the chance of success is so poor. A chance Elizia believes everyone will take.
She heads to find Koenig and the Interrogator uses a device to read his mind, and find out about Moonbase Alpha. The Interrogator says Koenig’s people will come for him. Elizia says they can have him. The Interrogator is concerned, because Koenig knows the truth about their home planet. Elizia wants everything extracted from Koenig’s brain. If it kills him, he will have a handsome funeral.
Crael and another prisoner arrive in Elizia’s throne room; the other is going to use the transbeamer to return home as he’s been a model prisoner. He dies shortly after arrival. Crael speaks to Elizia; they haven’t heard from any of the released prisoners and new ones are no longer being sent. And they no longer speak to their families directly. People are getting suspicious. Elizia dismissed this.
Heading back to see Koenig, Elizia decides he’s appealing. She also wonders how he resists the nerve bacteria. The Interrogator is having some problems reading parts of Koenig’s mind. And thinks they should tell the prisoners the truth. Elizia does not. And she isn’t worried if Koenig tells the other prisoners the truth for they won’t believe him and her guards are loyal to her.
So, Elizia is busy killing off the few remaining survivors of her people rather than admit the truth. Fraser and Albie are heading to find Koenig, and she’s not going to tell the truth to them either.
None of the regulars, bar Koenig and, to a much lesser extent, Fraser, appear directly in this episode, due to “Dorzak” being filmed at the same time.