Ghost Anlace is a war pony. His purpose in life is to fight for Equestria, and he does so with bravery unrivaled by any. But when he's injured a few months before the long war against the Zebrae ends, his purpose in life is questioned. What use is a war pony if there's no war to be fought? Now he has to start his life over with his injuries, extreme distrust, and paranoia in tow.
As a war hero, he's given a choice of where to live. Disdainful of the high society life in Canterlot, he chooses to settle himself in Ponyville, a primarily Earth Pony town. He stays out of public view, choosing to wander the streets at night. Over a long period, his unwillingness to be part of Ponyville's humble cheeriness fades somewhat. Some of his stoic demeanor fades as well. He goes on a few adventures and makes a few friends along the way, but none of them know his complete past. If they did, Ghost is sure, they would hate him.
As he slowly assimilates into living a normal life, Ghost begins to wonder what he was born to do. Surely he couldn't have been born just to kill and maim? And just as he begins to explore other paths, the Zebrae war flares up again. Now, caught between what he was assured was his purpose for so many years and his new life and friends (and maybe a mare who could be more), he has to make his choice. But as the war causes more and more casualties and the pleading from the military turns to demands, Ghost discovers that he may not have a choice at all...