It has been almost a century since Twilight and her friends had discovered their destiny, and Celestia has been wracked with constant regret over the fate she has condemned her friends to. Luna looks to those very ponies to help Celestia smile again.
Celestia and Luna were born as earth pony foals in a dangerous world. They must rise from nothing to become the princess we know, upsetting chiefs, gods, and the very forces of nature in the balance.