This story is a sequel to Windfall

A brilliant mind discovers a problem in search of a solution, which leads to inspiration, which leads to invention, which leads to a technological/magical advance that will in time forever change Equestria.

Sequel to Windfall, set three years after the events in that story.

This story is a sequel to Upheaval: Breaking Point

Following the events of Breaking Point, Twilight Sparkle and her friends discover that Equestria's demise may not come from an enemy invasion, but from within. The Barrier Lands and the Heartland begin the slow and uneasy process of reuniting into a single Equestria, but this long-delayed joining is already in danger at its conception.

With Celestia's power in her grasp and her agents by her side, the wheels of Black Rose's plans for Equestria's future continue to turn. However, her brazen gamble has done more than just bring down a centuries-old barrier. Ancient powers begin to stir: the remnants of a dark period in Equestria's history, the immortal inhabitants of Celestia's homeworld, and a rising tide of darkness coming ever closer.

Equestria is a land of magic and harmony, a peaceful realm ruled by immortal and benevolent monarchs. At what cost is this possible?

Following the discovery of a strange and powerful device, Twilight Sparkle is whisked away to the edges of a land she thought she knew so well. Here, surrounded by ponies whose very existences have been kept secret, she must contend with vicious enemies, hostile allies, and the truth.

Chapters 1-16 edited by KiltedKey

The Cutie Mark Crusaders ask Rainbow Dash and Fluttershy about what happened just after the events of the Cutie Mark Chronicles; specifically, what happened to Fluttershy and Rainbow Dash immediately after the race. Reluctantly, Dash and Fluttershy delve into a tale. A tale of a young Fluttershy's amazement at the world she had landed upon, and a filly Dash's desperate quest to save her from that most evil of places: THE GROUND.

Applejack had long since taken the Hearth’s Warming Eve story for fact. When she and Fluttershy find themselves in an untamed wilderness, they’ll learn that not all history is preserved. In their struggle to find their way home, the two will unearth secrets unknown to any living being, pony or otherwise.

Half a world away, the others have problems of their own. As Rainbow Dash struggles to discover exactly what she is to her oldest friend, Twilight must face the stunning truth about her long-time mentor.

In the end, what is lost, and what is found?

Twilight is invited to Canterlot to compete with some of the greatest magicians in the world for the Moonstone Cup, a prestigious award for the most powerful and skillful magicians, unicorn and otherwise. Can she win? What sort of competition will she face?

Awesome cover image was taken from NoOneBahtim

Windfall takes place seven years after FiM's main timeline. The Elements of Harmony have gone their separate ways, but are still close, and all the girls come running to be there on the eve of Fluttershy bringing her first foal with Big Macintosh into the world.

If you enjoyed this story and this fanfiction future extrapolation, please consider reading the sequel Earth & Sky