Daybreaker and Nightmare Moon are more than just "evil" alter-egos of the royal sisters - they're manifestations of powerful desires. Any desire, if strong enough and if suppressed for long enough, can cause them to appear.

For years, Luna and Celestia have denied their feelings for Twilight Sparkle. Their alter egos have grown impatient, and now they're ready to emerge and claim Twilight's heart - but when they both emerge at the same time, they find themselves battling one another for the right to her love.

Will their battle consume Equestria? Or will they find a more pleasurable way to settle things?