Blasted out of its ancient orbit round Earth by exploding atomic waste which had been stored on its surface, the moon and its captive Earthmen hurtle into the vastness of space.

The inhabitants of Moonbase Alpha discover that they are still alive and are able to continue their life support systems. They even have the remnants of the Eagle fleet of space ships with which to evacuate to a New World, should such a planet be found. But the prime requisite in this totally alien situation is the will to survive, the need to retain some form of normality. So, when Cynthia Crawford successfully reaches the end of her pregnancy, all seems to be re-establishing itself into an acceptable order.

But after the new-born baby is horribly mutated and its mother killed, Alpha's commander John Koenig, realises that they are in the hands of an alien force, on the run from its own planet, which threatens not only to commandeer the entire moonbase, but also their bodies...

Novelization of the season 1 episodes "Alpha Child", "The Last Sunset", "Voyager's Return" and "Another Time, Another Place".

Released in the U.K. and in the U.S. in 1975.