How do you end an alien occupation? Any way you can.

An untested nano-weapon has rid the world of its alien oppressors, but humanity's jubilation is short lived. Now, facing a one-two punch of alien retaliation from orbit and an out-of-control and rapidly evolving nano-weapon that sees all life on Earth as food, humanity's last hope for survival resides with the terminally-ill and possibly insane CEO of the world's largest mega-corporation, a small group of surviving aliens who want only to get off the planet before they're eaten, and a pair of cybernetically-enhanced human collaborators more interested in looting than saving the world.

Any way you look at it, humanity is doomed.