Princess Celestia has failed.

A thousand years have passed since the greatest tragedy of her long life. A thousand years to search for a way to unlock the truth of the Elements of Harmony, and free her sister from madness. A thousand years wasted.

Now, as the sun sets on the eve of the longest day of the thousandth year, it falls to her to face the darkness once more. Assailed by doubts and fears, Celestia is certain of only one thing: that the sun will rise again.

Even if it means the moon must fall.

Set in the same timeline as the war with Sombra in the Season 5 finale.