In 2001, an alien species known as BETA invaded Earth. Over the past 20 years, they have conquered most of the Eurasian continent and decreased the world population by billions. As a response to this threat, humanity has advanced the development of tactical weapons (machines). Elite pilots from around the world are gathering at a UN base in Alaska called Yukon for the Prominence Project, which is a joint effort between Russia and America aimed at researching and developing tactical weapons against BETA. The job of these pilots is to test the prototypes, sometimes involving pitting one machine against another.