They came from deep space. They came to destroy us. Fifty years ago, bloodthirsty aliens devastated the Earth. Most of humanity perished. We fell into darkness. But now we rise from the ashes. Now we fight back. Marco Emery was born into the war. After his mother is killed, he joins the Human Defense Force, Earth's ragtag army. Emery must survive basic training, become a soldier, and finally face the aliens in battle.