Sunset Shimmer visits the Castle of Friendship, and inadvertently discovers something that Twilight would normally keep hidden under her bed... except that since this is a pony princess we're talking about, it's nothing remotely resembling normal.
One day, Twilight Sparkle discovers something amazing about her friend Sunset Shimmer. She's a magical talking pony! This requires investigation! Science! Possibly a full-body physical! Or maybe she'll just ask her what's up with that.
The story continues several weeks after the Rainbooms’ crushing victory over the Dazzlings at the Battle of the Bands, with an emotionally ambivalent Sunset Shimmer uncertain on what to feel about her brief and yet heated affair with Adagio Dazzle.
Sunset Shimmer doesn't remember what happened at the last night's party. And worse yet, she can't remember just which one of the Twilight's she slept with
Twilight Sparkle hears a lot of things from Sour Sweet, who always shows off her fun life experiences. Once, ''Kissing'', is mentioned, Twilight takes interest onto it. After scoring a date with help from Lemon Zest, Twilight had to get some help.
Alcohol can make anyone do stupid things. Like one of your best friends. Sunset and Rainbow now have to decide where that stupidity is going to take them.