Optimus appears again in the 2011 film "". Optimus receives his own armory consisting of weapons and flight tech that transforms into a trailer for him to carry in vehicular form. After assisting NEST operatives in fighting Shockwave at Chernobyl, Optimus learns that the humans have concealed the discovery of an ancient Cybertronian ship on the moon. He revives his old mentor, Sentinel Prime, with the Matrix of Leadership. However, Sentinel Prime later betrays the Autobots, murders Ironhide, wipes out most of NEST, and brings an army of Decepticons to Earth with Space Bridge Pillars. During the battle of Chicago, Optimus kills Shockwave, the Driller, and many Decepticon Protoforms. Finally, Optimus challenges the traitorous Sentinel Prime and they engage in a fierce duel. At first, Optimus appears to have the upper hand, but Sentinel eventually overpowers him and severs his right arm. However, before Sentinel can deliver the killing blow, Megatron attacks and severely injures him, having realized that he will never be able to remain leader of the Decepticons as long as Sentinel is at large. Megatron attempts to make a false truce with Optimus, but Optimus doesn't fall for it and attacks Megatron, decapitating him with his battle-axe. Optimus then bitterly executes the wounded Sentinel with Megatron's shotgun. With the Decepticons defeated and the war finally over, Optimus and the Autobots accept Earth as their new home.