Moonbase Alpha finds itself caught up in a war between two planets.

The Moon is brought to a halt near a planet wiped out by nuclear war.

Biologist Dan Mateo manifests a bizarre murderous spirit while trying to communicate with with his plants: a spirit that kills anyone in its path.

The Moon plummets into an energy field that is evolving into a vast living brain... and sends antibodies to destroy the "invader" before it is wiped out.

An alien scientist and his daughter capture the "primitive" John, believing him to be the missing link in their evolution.

An alien spacecraft attempts to procure Alpha's computer data by "possessing" a crewman. When he dies, the aliens possess Helen to do the same thing.

Moonbase Alpha is attacked by a sentient war machine, Gwent, that demands that they keep its elderly creator contained within it alive.

The Moon gains a breathable atmosphere and the Alphans prepare to settle their home's surface. However, John suspects the aliens who provided the atmosphere.

The Alphas travel to their own future when they return to Earth.. and discover that it's a wasteland with a duplicate Moon orbiting it.

John, Helen, and a landing party explore a primitive planet and going missing. Another landing party find them... living among the savages on the planet, and evolutionary regressed to similar state.

An alien spaceship heading to Earth crashes on the Moon, and as the inhabitants make repairs they offer to take one Alphan with them. But at what cost?

An Eagle returns from a promising new planet with a strange passenger: Leo Russell, Helen's husband who died five years ago and warns the Alphans not to land on the planet.

The aliens find a psychopathic immortal alien banished by his own people, who plans to begin his "experiments" anew on his rescuers.

The Moon approaches Piri, where the Guardian offers them an idyllic life if they abandon their home and join it. Only John realizes that Piri is a trap from which they may neve escape.

The Moon is attracted by the gravitational force of a black sun, and there appears to be no escape for all but six crew.

The Moon crosses paths with a Darian generational ship. One half of the population lives in savagery, and the other half are sworn to preserve their race no matter what.

Tony Cellini, the only survivor of a deep-space probe, claims that an alien creature consumed his other three crewmen… and now Moonbase Alpha is approaching the same graveyard of alien spaceships.

The first child born on Alpha ages five years in a matter of days, and then an alien fleet arrives to make the Moon its own.

Voyager One crosses paths with the Moon, and its creator helps to stop it before its lethal nuclear wake wipes out Alpha. However, an alien fleet from a planet destroyed by the waste comes looking for the probe and its creator seeking revenge.

The Moon comes to a frozen planet inhabited by seeming immortals who invites the Alphans to join them.

An alien war fleet declares the Moon an invading virus and launches unrelenting attacks.

When the Moon heads directly for an alien planet, its queen convinces John to let the collision occur for the sake of her people's evolution and the Moon will be unharmed. Now John needs to convince his own people of the same.

An alien life force invades crewman Anton Zoref, transforming him into a mutated beast that seeks heat at all costs... and his next target is Alpha's nuclear reactor.

On Moonbase Alpha, the strange deaths of workers is being investigated which leads to the discovery of energy leaks at 2 different sites where Earths atomic waste is being stored. A race ensues to move waste at the second site before a catastrophic event occurs.