Dr. Russell's long-lost husband, Lee, appears on an Eagle returning from an Earth-like planet. He warns that the planet is not for them and that a power greater than they can understand will destroy them if they go there. Koenig must decide whether to listen to Lee's warning or evacuate the Moon before it's too late.
A call for help reaches Moonbase Alpha from the survivors of a dying world. The world is one that has been flying through space for 900 years with contrasting inhabitants. Some have never changed while others have reverted to barbarism. Does this new planet represent hope to the Alphans or something potentially dangerous?
A large group of objects suddenly appear in orbit around the moon and when one is retrieved by an Eagle sent to investigate, it found to contain the cryogenically frozen body of a young man. The man pleads for the Alphans to help revive his frozen colleagues though his pleas may not reveal all of his future plans.
Alpha' s water system needs a rare mineral named Milgonite and scanners detect quantities of it on a barren planet the moon is passing. When Koenig leads a party to the planet to obtain the mineral, the Alphans discover that the rock structures on the planet are sentient and have a need for water, which they intend to take from the Alphans themselves!
Koenig, Maya and Tony visit the planet Luton, a pluce lush in plants and vegetation. However, Maya and Koenig quickly find themselves in trouble over their innocent actions of picking flowers and eating a few berries. The two are forced into a dangerous trial by combat by the planet's rulers to prove their innocence with a possible outcome of death.
A survey below the moon's surface reveals a stasis chamber that the Alphans were unaware of. The chamber is found to contain two aliens, a man and a boy, in suspended animation. Once revived, the man identifies himself as Petrec and the boy Etrec and says they are emissaries from the planet Archanon. As Etrec is befriended, Helen discovers the two have a shared genetic disorder that may spell doom for everyone at the moonbase.
The people of Moonbase Alpha are suprised by the sudden appearance in their midst of a man named Magus, who claims he was responsible for the moon's ceasing to move so he could speak to the Alphans. Magus says he has created a planet that is the equivalent of a second Eden and transports Koenig, Tony, Maya and Dr. Russell there for them to see the world. However, the four quickly learn the real truth behind the sights that they see and the peril they face.
An engineer working below the moon's surface in search of a rare mineral needed for Alpha's life support system and the building of an artificial heart for his wife starts to become unbalanced from the stress and pressure weighing on him. To that end, he undertakes a course of action that endangers many even as Koenig wonders if his rantings might be actually coming true.
Koenig explores a planet that was devastated by some sort of weapon that killed all the inhabitants but did not affect the plants or destroy any buildings. He discovers that there is life on one of the moons and when he goes to investigate, he crash lands, and realizes that the moon is a prison and the inmates don't know they have no one to go home to.
The Alphans hopes of resettling on a planet of their own seem to be within reach when a seemingly uninhabited and life sustaining planet is located. But when they learn that the planet is already inhabited by a powerful immortal being, it quickly becomes a fight for survival where only the victor may escape alive.
The seven minute clip features only Zienia Merton reprising her role as Sandra Benes delivering a final message to Earth as the only crew member left while a massive exodus to a habitable planet takes place with the rest of the crew. This basically gave the series the finality it never had in its initial run.