It had been a while since Twilight had visited her friends through the mirror. Almost 2 years, in fact.
With this in mind, once she's finally able to clear her schedule, she ventures into the other world, eager to meet her friends once again, especially Sunset Shimmer.
The only problem is, when she goes through, she finds herself thrust into the middle of an unexpected conflict, involving her friends' country being invaded by another.
Caught up in the unexpected, Twilight will have to do her best to help her friends through this ordeal, or else they just might perish.

After all, the skies have no mercy.