Several years after Sam had settled into a peaceful life with Carly, Optimus Prime and the last of the Autobots leave Planet Earth after they had destroyed the last of the ruthless Decepticons. They travel back to Cybertron after destroying the Decepticons and live as quiet a life as they could. But it wasn't meant to be.
A few months after returning to Cybertron, the Autobots tell Optimus of an old Autobot research lab that was researching into parallel universes, and that they had found a type of Space Bridge that took them to a parallel universe. They said the Space Bridge was also operational. Optimus and his Autobots go to the research lab and check it out.
After typing some commands into the computer controlling the Inter-Universal Space Bridge, the Space Bridge opens up. According to the Space Bridge computer, it was going to a universe called the Shauwla Universe. Optimus and his Autobots step through the threshold of the Space Bridge and are transported to a planet in the Shauwla Universe which, when they surveyed the landscape, they determined that it was Planet Earth. But all of the buildings were ruined as if by nuclear bombs. Optimus and his crew decide to transform and drive toward the source of the signs of life that Ratchet had detected.
Our story begins as Optimus and his Autobots are driving towards the source of life, about three hundred miles out from where they had arrived. We begin when Optimus and the Autobots were halfway to the source.