Source

SGT Jennings dropped into New Mombasa to take over a Covenant cruiser. When a lucky Anti-Aircraft shot takes away his ability to control his pod, he careens end-over-end into a slipspace portal, and emerges in Equestria.

Be warned, there is more cursing in the beginning then there will be later, due to an all-military environment in the beginning.

Rainbow Dash is forced to confront the things that she locked away in the recesses of her memory, and her friends are the only ones that can save Rainbow from herself.

Cover image is from Peanuts. I do not have any connection with Charles Schultz.