Mankind is at war with the Strogg, a hostile alien race that attacked Earth. In response, humanity launched a strike on the Strogg homeworld...it failed, but you survived. Outnumbered and outgunned, fight your way through fortified military installations and shut down the enemy's war machine. Only then will the fate of humanity be known.

Includes "The Reckoning," "Ground Zero," and "Call of the Machine" expansions.