This story is a sequel to The Sombraverse: Prelude

Twilight Sparkle and Spike found themselves in a desolate, war-torn Equestria at the hooves of Starlight Glimmer. They saw the toll King Sombra's armies have taken on the world.

Now they're trapped there by the claws of something much, much worse. After a strange mare steals the spell, Twilight and Spike find themselves at the mercy of an otherworldly foe. They've been told they won't be free to return to their own time until they complete a certain task for him.

Not only that, this world seems to be changing them as well. Twilight can't seem to get a handle on her anger, and Spike's body is undergoing changes he can't understand. As the wear of a world at war drives them apart, the only thing keeping them together is this world's Applejack. Cold, driven, and intuitive, she may be part of what Equestria needs to topple the Shadow King for good.

After all, there's more than one monster lurking in the shadows, and the only way for Spike and Twilight to set things right in their own timeline is to save the world in this one.

Book One of the Sombraverse saga.