Team Sonic are called upon to take on Shadow, who has reawakened after 50 years. This was done by Gerald Robotnik, grandfather of Ivo Robotnik, as both Gerald and Shadow want revenge against G.U.N. for the death of Maria, who was Shadow's friend. After forming a brief alliance with Ivo and Agent Stone, the two join them in their evil plans. Team Sonic enlist Tom and Maddie to London to help them break into G.U.N. headquarters. Shadow injures Tom, driving Sonic to get revenge and Kaleb tries to stop him. Knuckles tell him where he kept the Master Emerald with Wade so that he can become Super. The Robotniks bring the Eclipse Cannon into space to destroy the world. Sonic fights Shadow instead Shadow kills him, but holds back and realizes revenge will not solve anything. Sonic, Kaleb who finds and apologizes to Sonic and Shadow join forces to stop the Eclipse Cannon. Gerald tries to kill Ivo, with help from Tails and Knuckles, Ivo uses Sonic’ supercharged quill to zap Gerald and send him into the energy field. The brothers and Shadow are able to hold off the blast while Ivo, Tails, and Knuckles redirect the blast. Ivo decides to stay behind to prevent the Cannon from exploding Earth, with Shadow pushing it away. Ivo sends a farewell stream to Stone to thank him for being his loyal friend. After returning home, Tom recovers from his injuries and Team Sonic celebrates victory. Sonic and Kaleb end up running all the way to New York and encounter an army of Metal Sonics and Amy Rose.
