"With the All Spark gone, we cannot return life to our planet. And Fate has yielded its reward: a new world to call home. We live among its people- hiding in plain sight, but watching over them in secret. I have witnessed their capacity for courage, and though we are worlds apart, like us, there’s more to them than meets the eye. I am Optimus Prime, and I send this message to all Autobots taking refuge among the stars: We are here, we are waiting."
--epilogue from “Transformers” (2007)
With those words, a beacon was sent, alerting the cosmos to our presence in a way we never imagined. Some Autobots responded, but more Decepticons- learning of the death of Megatron- came to seek revenge, to take the throne of their faction for themselves, or simply to see that their leader was truly gone and wonder what would happen next. Two years after the All Spark Cube was destroyed, the Autobots have sought asylum in the United States, and they work closely with its government to form N.E.S.T. (Non-biological Extraterrestrial Species Treaty) to cooperate in tracking down arrant Decepticons hiding on Earth and keep the human race unawares amidst growing conspiracies. But with increasing alien activity across the world, it is suspected that the Autobots themselves may be encouraging Decepticons to come to Earth by their very presence here, and the relationship is beginning to become strained. Meanwhile, Sam Witwicky has gone to college, but on his first day he begins uncontrollably spouting gibberish like his great-grandfather over a hundred years earlier. It is discovered that he now retains, deep in his mind, the full knowledge of the destroyed All Spark Cube! Learning of this, the Decepticons steal the last shard of the All Spark, and rebuild Megatron. Teleporting himself to another dimension, Megatron consults with his master- an ancient and evil traitor known as The Fallen, who is the leader of all Decepticons. The Fallen plans to harvest Earth’s Sun for Energon at the cost of destroying the planet as he would have thousands of years ago were he not driven off by the Dynasty of Primes- the original leaders of Cybertron. But to do this, The Fallen must recover the long-lost Matrix of Leadership from the secret Tomb of the Primes- which Sam now holds the only key to finding- to activate the Solar Harvester. And the last surviving descendant of the Dynasty- Optimus Prime- is the only one who can stop The Fallen now…
(film summary by EVA_Unit_4A)