A.J. Merak – författare

Earth was threatened with attach from the huge space-fleets of the Hundred Suns of Andromeda - an attack that the Terran Fleet could not hope to defeat.Only one chance remained to prevent Earth''s destruction, and that was the chance that a skilled and experienced saboteur might just have time strike his blow before the enemy could launch the attack.It was Captain Blair whose mission this became, and it was his ace-saboteur who raced against death in planet after planet, as the zero-hour approached when Earth would face the attacking fleets of DARK ANDROMEDA.

The logical outcome of the space race, and the preliminary step towards the Moon, was the manned satellite, the Big Wheel moving in a stable orbit about the Earth, integrating the data necessary for a landing on the Moon, and eventually acting as a fuelling station for the Lunar rockets.After several failures, the station is ready, but even there, danger exists, unseen, unheard, invisible and terrible. Forced to exist in the belt of cosmic radiation surrounding the planet, men die within weeks from aplastic anaemia. Seeking a solution to the problem, Doctor Paul Russell is sent up to the satellite and here learns of the two men from the previous crew who vanished without a trace after spotting an unidentified spaceship in orbit further out from Earth than themselves.