While Cerebros follows Optimus to Vector Sigma, the other Autobot Headmasters join Hot Rod in finding the Matrix, while Galvatron launches an attack on Autobot City to stop the Autobots from obtaining it. Hot Rod eventually finds the Matrix in an energon storage facility, and after a failed attempt by Mindwipe to retrieve it, leaves for Cybertron with the Trainbots and Autobot Headmasters. At Vector Sigma, Optimus is ambushed by Cyclonus and Scourge, but rescued by Cerebros. Hot Rod and the other Autobot Headmasters arrive, followed by Galvatron and the Decepticon Headmasters. Alpha Trion merges with the Matrix in Hot Rod's hands, fully recharging it and transforming Hot Rod back into Rodimus Prime. After the two Primes drive off the Decepticons, Vector Sigma goes critical, and, despite Galvatron's attempt to kill him and Rodimus' own pleas, Optimus merges his spark with Vector Sigma, stabilizing it at the cost of his own life, leaving Rodimus in command of the Autobots once again.