Follow Luna, Rarity, Celestia, Rainbow Dash and many more beloved characters as they are whisked into the shoes of the characters from Halo's The Mona Lisa. After salvaging a dying prisoner from Halo's debris played by Lightning Dust, the Ponies of the UPSC Red Horse are left curious and hungry for answers. Commander Princess Celestia and the AI Discord order Sergeant Luna and a squad of seventeen Ponies to investigate the ship Lightning Dust came from: An abandoned Prison Ship known as The Pony Lisa. So what happened on board The Pony Lisa? Did the Griffins playing the roll of Covenant take her over? Or was it just a prison riot? The answer is far more disturbing than anypony could have imagined. Whilst finding a few survivors on the way, and Luna fighting a separate battle in her head, the dwindling squad must push through a horrific infestation and destroy The Pony Lisa's nav systems to stop the evilest thing in the galaxy from locating colonised worlds.