Optimus Prime is back on Earth for the first time since his rebirth on Nebulos! While his fellow Powermasters look into a giant robot attack on a small town (suspecting Decepticons at work), Prime must face the greatest challenge of his life. For Prime, the unthinkable has happened. he simply no longer cares about Earth and it's inhabitants! it's true - whereas he would once have gladly sacrificed himself to save human lives - Prime now simply wants to end the menace of the Decepticons... at any cost! Can Prime rediscover what he has lost? If not, the Decepticons may well have been granted their greatest victory!