In 2005, the war between the Autobots and Decepticons has culminated in the Decepticons conquering their home planet Cybertron, while the Autobots operate from its two moons preparing a counter-offensive. Optimus Prime sends an Autobot shuttle to Earth's Autobot City for Energon supplies, but the Decepticons, led by Megatron, commandeer the ship and kill the crew, consisting of Ironhide, Ratchet, Prowl and Brawn. Travelling to Earth, the Decepticons attack Autobot City, slaughtering many Autobots and leaving only a small group alive including Rodimus, Kup (Transformers), Ultra Magnus, Arcee, Springer (Transformers), Blurr, Perceptor, Blaster (Transformers), and the human Daniel Witwicky. The next day, Optimus and the Dinobots arrive as reinforcements. Optimus single-handedly defeats the Decepticons and engages Megatron in a climactic battle that leaves both of them mortally wounded. On his deathbed, Optimus passes the Matrix of Leadership to Ultra Magnus, informing him that its power will light the Autobots' darkest hour, and dies.