In the 21st century, humanity colonized the moon and built a network of lunar outposts. In 2089, the Xenon Empire arrived and proved how quickly that achievement could be dismantled. Their assault shattered several outposts and came close to taking all of them. It did not quite reach Nectaris — the largest base survived with enough units intact to plan a response. The player assumes command of the Union forces, directing that counter-attack against the Xenon Empire with one objective: take back what was lost.