Disaster strikes Equestria when Celestia is found collapsed in her room alongside Daybreaker. Questions about how Daybreaker became real are only compounded when her personality becomes clear – she's an oddly affectionate goofball who's obsessed with math? Where's the destruction and chaos?
Celestia and Luna were hoping to retire soon, but now they have to handle this strange pony, who should be an embodiment of all of Celestia's worst impulses, but seems to want nothing more than to help everyone in Equestria. This drive to help, paired with Daybreaker's lacking restraint and common sense, along with her seeming inability to control what comes out of her mouth, add up to far more of a headache than either diarch expected to deal with in their final days of rule.
Good thing she's at least completely emotionally balanced. By the way, did you know story descriptions always contain at least one lie?
Cover art by the ever-impeccable Yakovlev-vad: https://www.deviantart.com/yakovlev-vad/art/Two-sides-of-one-crown-826401866