A desperate attack by Doctor Eggman on Sonic & Co. during a party lands them all in a new adventure, this time on a brand new world. With the Master Emerald shattered, and the Chaos Emeralds scattered, they must now band together with new friends to collect them all. But as always evil looks to gain control of the powerful gems, and this time they're backed already by incredible power. More than two worlds are at stake in the upcoming confrontation: Can the Mobians and Equestrians stop the evil Emperor and his minions? And who is the stranger that joins them in this quest? How will his appearance change the course of everything?