One year after the events depicted in the 1984 show, humans and Autobots are rebuilding Earth as well as Cybertron. Then all of a sudden Galvatron and Decepticons attack with full force. A mysterious spaceship shows up mid-battle.
Scorponok takes command of the Decepticons, and the Autobot Headmasters must thwart his plan to seize control of an Earth satellite that can harness the energy of the sun.
Spike attempts to negotiate peace with Galvatron, but all is not as it seems as the Decepticons, now joined by the Horrorcons, plan their next evil scheme.
The Decepticons' newest target is the energy-rich Twin Star planetary system, but before the Autobots can come to its defense, the Headmasters are going to have to settle their own arguments first.
The Transformers' interplanetary travels bring them to planet Darhos, where the Autobots aid desperate prisoners in overthrowing the Decepticons and the planet's decadent ruling class. But that's not all - the key to defeating Scorponok is also hidden on this world.