When Sweetie Belle finds an old mirror in the attic of Carousel boutique, she takes it back to the Cutie Mark Crusaders clubhouse. But a vortex opens from the mirror and suck the Crusaders into it, taking them back in time 2000 years ago! Now the Crusaders must hurry and find a way back to their time before the 13 stars aline, or they'll be trapped in that time forever. Along the way they meet new friends and Babs falls in love with a colt named Sliver Gravel. And the greatest truth is revealed... the origin of the Cutie Mark!