Set far into the future the Earth has been overrun by an extremely aggressive alien race. Many survivors live in large bunkers under ground. One of them is military rookie S.U.M.1. He is tasked with a mission to resurface after a lifetime of being under ground in order to save a group of survivors. Unprotected and on the run from aliens, will the group survive? It's up to S.U.M.1 to make it happen.