Amnion

On a desolate rock drifting through space are the ruins of an outpost, it's inhabitants slain and entombed in ash. Save one; an old soldier cut off from the rest of humanity with no orders, no means of escape and no purpose. He dwells inside the remains of a forsaken house like a favourite memory, and it keeps him alive. Yet the time to move on will soon be upon him. For while focusing his efforts on the dangers he's kept out, the dweller will soon be overwhelmed by those kept within.