Trixie returns to Ponyville a year after she was defeated by Twilight for a second time. She expects to find the place how she remembered it, but instead finds something horrifying. A terrible darkness has swept over Ponyville, a darkness that reaches all the way to Canterlot. Trixie finds that all the ponies she used to know are now corrupted by sin. The mane six and Princess Celestia had become the seven deadly sins. Trixie must now find a way to save Equestria and bring the ponies back to the light. She'll find aid in the most unlikely of friends in this dark journey.