After the stress of being a ruler and now teacher is becoming a bit overwhelming, Princess Twilight is offered a one-on-one holiday with Sunset Shimmer.
With everypony else unavailable, Spike volunteers to babysit Flurry Heart for the day. Things go well, but then Sweetie Belle comes and shakes things up by deciding to help, too. The day goes on, and they spend it like their own, little family.
Moons after their fallout and guilt, Princess Celestia jumps through the portal and finds Sunset Shimmer! Or does she? The girl she finds certainly looks like Sunset, but the girl claims to be just a simple musician who doesn't know Celestia at all.