After weeks of uneventful flight, the Alphans once again journey into perils which threaten their imminent annihilation. The Moon Base becomes the target of unknown aliens determined to secure the Alphans' vital power supplies to ensure their own survival.

A bizarre, jewel-like asteroid containing the microcosmic Heart of Kalthon which demands vast energy supplies to convert it to its original size...

An evil, ghost-like visitor from the Anti-Matter Universe seeking to materialise his dying race in the Positive Universe...

Strange humanoid life-forms kept in suspended animation and doomed to die unless awoken...

A mysterious dust cloud protecting a monstrous creature sent to steal the Alphans' life support system...

Novelization of the season 2 episodes "Seed of Destruction", "A Matter of Balance", "The Exiles" and "The Beta Cloud".

Released in the U.K. and in the U.S. in 1977.