Henry Masterson, creator of the Headmaster exo-suits, is fired by Isaac who states that Sumdac Systems doesn't make weapons of war even when it's exo-suit makes one of Isaac's robot models unstable. To take revenge on Isaac, Henry becomes Headmaster and plans his revenge by taking over Bulkhead's body. The Headmaster eventually succeeds in taking over Bulkhead's body, and fights the Autobots using it and weapons built into the Headmaster unit. He also causes the city's generator-core to overload, threatening to destroy the city. By the time the Autobots defeat Headmaster and knock the Headmaster unit off Bulkhead, the overload is at the point where the only way to stop it is to manually push the containment-grid back into position. However, nobody can survive the conditions inside the core, so it's essentially a suicide mission. At first, Optimus plans to do it himself, but Bulkhead has the idea of creating a new robot to do it. The Autobots create a patchwork robot in time, and Sari animates it with her key. The robot succeeds, and its melted, damaged, inanimate remains are put on display.