The Transformers: The Headmasters begins with Galvatron leading a new group of Destrons in an assault on Seibertron, prompting the arrival of the Cybertron Headmasters, led by Fortress (Cerebros, the head of Fortress Maximus). It is revealed that Fortress left Seibertron millions of years ago in search of energy and has finally returned home. Fortress explains that the Cybertron Headmasters originate from a planet called Master, where human-sized robots built themselves Transformers-sized bodies and can transform into the heads of the robots. The Headmasters have now joined the Cybertron-Destron war, uniting with the Cybertrons to counter the Destron threat.