Humanity has colonized the universe to a great extend, with its frontiers expanding one planet after another. The border ones are a theatre for war and conflict that guarantee the peace in the inner territory. A great menace is pending as an alien robot race is preparing an invasion.

Humanity has colonized the universe to a great extend, with its frontiers expanding one planet after another. The border ones are a theatre for war and conflict that guarantee the peace in the inner territory. A great menace is pending as an alien robot race is preparing an invasion.