S04:E03 - The Rebirth (Pt. 3)

With his son, Daniel and his friends, the Autobots captured, Spike finds a way to stop the Decepticons once and for all. The answer to saving his son and friends lies in the lost city of the Hive. With the help of Cerebros, Spike changes the lost city into an Autobot Headmaster named Fortress Maximus. Unfortunately, Galvatron opens the Plasma Energy Chamber and its energy overloads the Autobots as well as Earth's sun, causing it to go nova. Now, Spike is the only one who can save the Autobots and the universe by shutting down the chamber.