It's chaos in Sonic's world as he and his friends (Tails, Knuckles, Shadow, and Silver), race to stop the nefarious Dr. Eggman, who has acquired all seven Chaos Emeralds. The doctor believes he has their mysterious powers mastered, until they overload and open a portal not too different from the one that sent Sonic and his friends to earth years ago. Only this time, they don't end up on earth. They're in a brand new world, one with solar deities, mysterious forests, majestic cities, and, most notably, friendly, adventurous, colorful ponies, which they just happen to now be. They're in Equestria.

But Dr. Eggman was sent to Equestria as well, and the race for the Chaos Emeralds is on. But the doctor isn't alone. It's up to the combined forces of Sonic's team and the Mane 6 to protect their world from perhaps the gravest threat yet.

(Note #2: This story takes place in the canon world of MLP as of episode 13 of season 5 and a somewhat freak Sonic universe comprised of the Sonic Adventure games (and a slew of other Sonic games that will be mentioned) and the Sonic X TV series.)

(Cover art by Red Thunder on Deviantart)