Ribbon learns that the evil Nightmare Moon will return during the upcoming Summer Sun Celebration after one thousand years of imprisonment in the moon. She tries to warn her mentor Princess Celestia, but the princess ignores her and sends her to Ponyville to check on the preparations for the celebration. With Ribbon's new friends; Masquerade, Whizzer, Gingerbread, Derpy, Paradise and Thistle Whistle to help her and be her friends, what could go wrong?