What if humanity was diplomatically isolated from the Citadel races, left to fend for itself against the Batarians and other threats? This is an AU story of a humanity forced to struggle and fight for its place in the stars, with many points of divergence and some pretty significant changes made to the background lore. Contains violence and some mature themes.

In 1958, NATO and the Warsaw Pact come into contact with a hostile UFO. It seemed to defy the laws of physics with the way it moved and the way it's mass seemed to almost...fluctuate. In a joint effort, the two powers defeated the aliens, but only just. Now, the aliens have returned, and only one organization has any hope of stopping them: the Xenonauts.