In the 22nd century it was finally accepted that the Earth was dying due to a combination of factors including global warming, breakdown of the ozone layer, depletion of natural resources and a recent "flipping" of the planet's magnetic fields which will leave the surface open to the solar winds - as scientists now believe happened on Mars.

In response, a global conglomerate funded the construction of the ARK, a city-sized space ship in which is stored genetic samples of all life on Earth, together with the brightest and best of the population - 100,000 of them - all cryogenically frozen. The plan was to launch the ship into a vast elliptical orbit beyond the solar system, in search of a new habitable planet to colonise.

It is now the 24th century. The Ark is at the end of a 200 year journey, having found a new homeworld for its precious cargo, and is heading back to Earth in order to collect more survivors and transport them to the new world. They have sent a scout ship ahead - THE ARMSTRONG - a military-style ship, about the size of an aircraft carrier.

Her mission is one of reconnaissance - to check the status of Earth and report back to the ARK where decisions will be made about the next stage of the programme.

As the story opens we join the crew of the "Armstrong", entering the Solar System on a heading for Earth.