“The Beta Cloud” is episode sixteen of season two of Space: 1999.
A cloud is hovering above Alpha. Sandra says the range is constant, even though it seems to be approaching. In one of the corridors, a man collapses. Maya can detect hydrogen and nitrogen in the cloud and unidentifiable components. The companion of the man who collapsed contacts medical; it looks like he wasn’t the first to pass out.
Maya says the cloud is affecting everything. Scanners are malfunctioning, sensors are erratic. The commander seems unsteady on his feet. Dr Russell contacts Command Centre and says people are passing out all over. Koenig says it’s the cloud as someone else collapses and he finally succumbs.
Seven days later and most of the personnel have been affected by lassitude, depression and loss of will. Some seem immune. An Eagle was dispatched four days ago with one of those to the cloud to get samples for Dr Russell, but it never returned. However, in Command Centre. Sandra reports that the Eagle is returning. Even though it should be out of fuel. It doesn’t respond when they try to contact it and Maya reports no life forms.
Tony contacts medical; he wants to talk to the commander. Koenig is out of it, though. Sandra reports the Eagle is landing and Tony contacts security to see how many personnel they have. Three. He wants one to go to the travel tube and the other two to Command Centre. He and Bill Fraser head to meet the Eagle.
The Eagle seems to be empty. Apart from a large creature. The guard man shoots it; naturally to no effect. Tony and Bill get away; the guard does not. Tony wants the two remaining guards posted outside the travel tube with heavy rocket guns.
Sandra reports activity in the cloud. Maya detects something solid within. Tony and Bill exit the travel tube and Tony tells the guards to shoot anything that comes out. They return to Command Centre, in time to catch a voice that demands their life support system. Even though Alpha can’t exist without out. According to the voice, they can’t either. They’ve sent for it and the voice activates Alpha’s screens.
The creature comes out of the travel tube and the two guards have no effect. Tony tells Maya and Sandra to head to medical, then contacts Dr Russell to let him know when they arrive. Once they do, Tony orders the computer to turn all doors to his voice command only. The cloud voice says it won’t work. The creature breaks into Command Centre and Bill and Tony flee. The voice tells the creature that life support is elsewhere. Tony will try and lure the creature away as Bill heads to life support.
Commander Koenig and Alan get out of bed. Maya wants to help Tony. Koenig tries the door but it doesn’t open. He heads back to bed and tells Alan to take over. Alan seems to be improving; he apparently became sick first. He contacts Tony who is going to lure the creature into the vacuum chamber, then pump the air out.
Tony lures it into the chamber and pumps the air out. Dr Russell collapses as she’s talking to Sandra. Tony, foolishly, decides to reopen the chamber to see if the creature is dead. It isn’t, and now isn’t locked in either. Maya changes into a mouse and heads into the vents. She finds Tony and the creature fighting. She tries changing into it, but can’t, and changes into something else that is coming off distinctly second best. Tony distracts it with high pressure carbon dioxide and both flee back to medical.
Sedating the creature is considered, and Dr Russell tells them how. She’s in bed and wants Sandra to take over. The creature is now heading for life support, and Tony and Maya head there too.
The creature is large and it seems unstoppable. Nothing seems to work (the actor’s next role was as someone also large, seemingly unstoppable and dressed in black – Darth Vader).