This story takes place two years before Power Ponies: Harmony Forever.

Back in the day, superheroes were celebrated by some. The others support the Super Purification Act. That's part of the reason superheroes conceal their identities, especially Twilight Sparkle a.k.a. the Masked Matterhorn. But when an old secret of Princess Celestia comes to light, Twilight must team up with other heroes to fight two threats. One full of darkness and the other full of insanity.