A changeling defect escapes into Equestria as another pony, having to face the life of a normal filly. Meanwhile, she writes in a small journal she finds. This is what she's written.
The war horse Onyx finds himself in a new land, far different from that of his previous masters. Thus he must adapt to life with his new master in this strange land.
What if harmony no longer existed, and those ponies who were left had to rediscover their true identities underneath what seems to be a dismal new world.