Many and strange have been the adventures of Moon Base Alpha and its crew since the atomic waste pits on the dark side of the Moon exploded and sent them careering out of Earth orbit, deep into unexplored space.

Always they have managed to overcome their perils and continue their strange Odyssey. Now, at last they seem to have reached the end of the road, as caught in a weird cone of force emanating from a sentient planet, they find themselves ageing at an incredible rate and powerless to break free.

A period of respite as the Moon seems to be passing through an empty area of space encourages the inhabitants of Moonbase Alpha to relax.

Part of the leisure activities includes a performance of Hamlet. Suddenly, as the ghost makes his first entry, his words are distorted into a grim warning to the Alphans to turn back or else. Many in the audience suffer hallucinations and a patient in the medical block goes beserk.

But there is no turning back. And there is still nothing to see. The medical team produces a drug which will at least partially counteract the hallucinatory powers of this strange force the Moon is being drawn towards, though some Alphans still die gruesomely as they cross the invisible barrier into the rogue planets orbit. More die, almost instantly aged to the point of senility, as they carry out essential repairs to outside structures of the base. The strange brain-like planet is steadily sucking energy from the Moon, from its own manufactured supplies and from its inhabitants, as it still is from the small planetoid the Alphans can see also trapped in its orbit.

Eagles are sent to investigate the planetoid, only for one of the crews to be trapped in a strange mausoleum, filled with dead aliens. Commander Koenig and his party rescue them, then he heads off for possibly his last mission — an orbit round the rogue planet. When he in turn is rescued, he is aged and suffering from the dreaded hallucinations.

It is a matter of time before the Moon is destroyed as the planetoid has been or can summon enough energy to destroy the rogue.

"TURN BACK, FOR DEATH AWAITS YOU!"

The chill warning echoes from the depths of the unknown, shattering the icy silence of space. But the bold Alphans must spin faster and faster toward an electrifying confrontation with their unknown enemy.

Ageless against the stars stands Omphalos.

A giant green "brain," this galactic monster spins a web of deadly horrors, trapping Alpha in a ghastly psychic war!