The storyline revolves once again around the Autobots and Decepticons. Some of the evil Decepticons awake the most dreaded and vivacious Decepticon of all, The Fallen! He had been lying on the core of the ocean for hundreds of years and now in the sequel he rises again.
This powerful and hefty new Decepticon is the major part of the movie. As the name suggest, the Fallen will help the Decepticons in war against the Autobots and humans. In this sequel, Megatron also rises from death. He supposedly returns with the help of the piece of Allspark left with Sam Witwicky.
While on the other hand, Sam is off to an East Coast College leaving his loved ones behind. His girlfriend Mikaela Banes is not going with him as well because she could not afford the college and neither is his beloved car Bumblebee going along with him as the college does not allow freshmen to bring a car to the college. Now, Sam is alone at college while Mikaela is working at a motorcycle repairing workshop. Bumblebee wrecks Witwicky's garage and ultimately has to leave the house.
The movie revolves around different countries of the world but the main focus is on Egypt. Sam sees a lot of flashes of the old Egyptian scripture when he touches Allspark, and he starts writing a lot of difficult Egyptian scriptures during one of his classes in college. It was concluded that the Transformers have ancient history on Earth.
And then the war of Decepticons versus the Autobots starts. Even the humans are dragged in the battle as the Decepticons want to destroy the world. Now the Decepticons want Sam because he has the piece of All Spark even though he wants to stay out of it, it soon becomes his war.
The Autobots help Sam save the Earth and his family once again. The Fallen joins the battle as well. A much more ferocious war is fought. Megatron wants information from Sam about the source of Energon on Earth. Mikaela is also involved in the encounter as she refuses to leave Sam alone in such time of difficulty.
It is implied that Optimus Prime might be killed during the war. The whole world is tangled in the combat. But the fans are now intrigued about the outcome of the battle. How many will survive? Will their hero Optimus Prime remain with them? Would Sam hold up against the Decepticons? Would Mikaela and Sam be together till the end? Every fan is waiting impatiently for the release of the movie.