He kills The Fallen; mutilates Megatron; and destroys the Sun Harvester.
Dark of the Moon‘s history lesson takes the Transformers story back to 1961, when the Ark, a ship from Cybertron carrying top secret inventions, crashes onto our moon.
Most of the rest of the movie is just extended battles between various Transformers.
It ends with the All Spark being extinguished, most of the Decepticons either dying or escaping, and Optimus Prime salvaging a small shard of the All Spark. The Transformers story continues more new history: the Primes, the original Transformers, traveled the galaxy creating Sun Harvesters in order to create more power like that in the All Spark. military and help track down surviving Decepticons.
Optimus Prime uses his Matrix of Leadership to revive Sentinel Prime.
Sam starts looking into the Ark and teams up with Sector 7 agent Seymour Simmons (John Turturro).
Determined not to allow the evil Megatron to get ahold of it, Optimus Prime sends the All Spark into space.
Megatron goes after it, but crashes into Earth’s Arctic Circle.
If Megatron and the Decepticons get ahold of the All Spark, they plan on using it to bring to life all of Earth’s machinery and wiping out the human race.On their home planet of Cybertron, there are two opposing factions: the Autobots and the Decepticons.The Autobots, led by Optimus Prime, are fighting to prevent the Decepticons (led by Megatron) from getting the All Spark, a powerful artifact that would grant unlimited power to whoever possesses it.During battles, Sam is killed, but the Primes appear to Sam in a vision, bring him back to life, and empowers the Matrix dust to revive Optimus Prime.Optimus Prime faces off with Megatron and The Fallen, who have revealed the Sun Harvester.He is discovered in 1850 by explorer Archibald Witwicky, who unknowingly activates Megatron.