Lyra gets tickets to bring BonBon and Ditzy on a tour of Canterlot. Their trip is cut short by an insane stallion named the Doctor who claims to have come from a separate universe. With a clock ticking, will anyone be able to save Canterlot from an invasion that has been in action for hundreds of years? Or will even the god-monarchs be brought down by a sinister force older than the stars themselves.