Moving at the speed of sound, keeping the world free from robotic tyranny -- it's Sonic The Hedgehog! The entire planet has been rocked by Dr. Eggman's Super Genesis Wave! Sonic wakes up to a world and a life he doesn't recognize! It's up to him to gather up his friends -- the Freedom Fighters -- and figure out what's been changed. Meanwhile, below his very feet, a new threat is threatening to burst out!