The year is 2670 and the Golden Age of Man has come to an end. Earth has been overtaken by The Scourge, a parasitic alien race bent on domination, slavery and exploitation. Humans are scattered across the frontier planets. Out of the ashes, the United Colonies of Mankind are rising again, to return to Earth and reclaim their home. They must prepare for bloodshed and war in reclaiming their home, and potentially an outright confrontation with the cyborg race of former humans, the Post-Human Republic. But the UCM is not alone - they have an alliance with the technologically superior alien race of the Shaltari Tribes. Will Mankind prevail against The Scourge?