In Sonic Riders, Sonic and his friends are on a mission to foil the evil Dr. Eggman and his new henchmen, the Babylon Rogues. Dr.Eggman has created the Ex World Grand Prix; a no-holds barred racing series where the fastest "riders" in the world participate in this tournament. Never one to turn down a challenge to prove his speed, Sonic and his friends join the tournament and uncover Dr. Eggman's true intentions.