After driving the Decepticons off Cybertron, the Headmaster's leader, Fortress (Cerebros), explains that the Headmasters were once Autobots who fled Cybertron during the Great War and established a peaceful new life on the planet Master. After the group honed the ability to transform into heads so they could control larger bodies, Skullcruncher, Mindwipe, and Weirdwolf rebelled under a mysterious figure named Zarak, only to be exiled from Master and later ally with the Decepticons...