Earth as we all know it's gone. A virus has destroyed the planet and rendered all its girls infertile, all however one. An elite crew of troopers are tasked with bringing the lady to security on the newly liveable Earth Two. However when they're compelled underground they discover themselves combating for survival from an bloodthirsty creature in a maze of ever shrinking tunnels. Because the crew's ranks begin to dwindle, the tunnels shrink and the ammunition run out, the crawl for survival turns into increasingly more determined.
