When Twilight attempts to expand her repertoire of magic, she gets more than she bargained for when she ends up switching Spike and Princess Cadence's minds, with serious repercussions should anypony find out. Between helping the Crystal Empire, helping the Magic Of Friendship spread through Equestria, and keeping Shining Armour and Flurry Heart happy, and finding a way to reverse the spell, the trio has more to worry about than ever before thanks to Twilight's recklessness.

Wish them luck.