When Trixie makes a lewd remark to Starlight Glimmer during their 'medal of honor' celebration, Starlight blasts the showmare into the next room in an effort to shut her up. Sadly, her efforts send not only Trixie to the next dimension, but also Princess Luna.

While Starlight is panicking back in Equestria, Trixie and Luna discover that they did not turn into humans upon passing through the mirror portal. Instead, they are now fillies.

Saturdays suck.