Space depth is not lifeless, they are insidious and dangerous. A strange race of aliens attacking earth ships, we can not find common language with them, and for the sake of survival, obliged to defend themselves. Once in trouble, a lone ship trying to fend off the alien attack. The ship has a weapon, but it is too weak to seriously affect the fight. The only chance for survival is to search for extraterrestrial technologies amid the wreckage of alien ships. These technologies can be re-seize the combat options naval guns, but the effect lasts long.