Nopony's perfect, not even Princess Celestia, she has made mistakes in her past that she regrets.
One of those mistakes will soon return to remind Celestia that the past can never truly be forgotten nor should it.
Someone is causing trouble in Equestria, but Celestia isn't moving from her castle, instead she tasks Twilight and Cadence to handle the problem.
Who is attacking Equestria and why won't Celestia do anything, what secrets is she hiding from her faithful student and loyal subjects?