It has been a very long time since anyone in the plane of Zendikar saw the eldrazi titan Emrakul.
Visions of a devastated land trouble Gideon Jura, who has decided to track down the last of the three monstrous giants. With Jace off to Innistrad and Nissa healing the plane along with Chandra (However she can), Gideon follows the essence which Emrakul left in her last hedron prison.

This leads him to a peaceful, new plane filled with strangely sentient creatures. However, Gideon can't allow himself to be distracted by this, since as every second goes by, the eldrazi titan becomes stronger and spawns a huge brood of all-consuming aberrations.

If you play MTG, but don't follow the story, here's the summarized story of the Zendikar block:
First
Second

You can read this story without knowing the MTG lore. But it's highly recommendable to do so in order to understand many keywords.

Have you ever imagined how you would've been if you were born in a different place? With other parents or circumstances? Flash Sentry had. And he had expected anything but this.

Couldn't find a fitting cover art...

There are stories with simple teachings in them; stories for foals with a happily ever after; Romance novels to picture nearly impossible but touching scenarios.

And there are horror stories which are supposed to scare ponies for a moment, disappearing in time and left alone for a new pony to listen.
The book Twilight found one day at her new library, was mistaken for one of those horror stories...

While everypony is growing and building a life, Spike notices that he is still a baby dragon, and will probably be for a long, long time. Not to mention that he had no dreams or expectations for his future, other than a not-so-realistic one: to be with Rarity.
On a desperate attempt to change his life and discover who he really is, a lot of depressing facts are unveiled. Can Spike withstand his fate and what being a dragon implies?