Five Autobots (Optimus Prime, Bumblebee, Ratchet, Prowl, and Bulkhead) find the fabled Allspark only to become a part of the long-lasting battle between the Autobots and their enemies, the evil Decepticons. A space battle ends up stranding the Autobots in the 22nd century Detroit where they take on roles akin to that of superheroes, fighting both Decepticons and human supervillains. The story takes place in Detroit, and the Transfomers' battle is renewed in this future city on Earth. Instead of being known as the Motor City, it has now become the Robot City due to Dr. Isaac Sumdac's non-alien robotic creations. Sari Sumdac, his 8-year-old daughter, is the main human character that the Autobots saved when they landed on Earth.
On Christmas Eve, Optimus Prime patrols the city in search of Soundwave. With Porter C. Powell selling Soundwave action figures, Optimus is paranoid that the real Soundwave is out there. When the Autobots drift off to sleep, they awake as full fledged humans. Now they must figure out what happened to them while dealing with a Decepticon onslaught.
The Autobots and the Elite Guard pursue Wasp for their own agenda for Wasp. However, Blackarachnia has Swoop capture Wasp in her latest attempt to get rid of her organic half. Jetfire and Jetstorm attack the Dinobots so Sentiel can get in, learning of Elita's fate while Wasp emerges as Waspinator. Optimus and Bumblebee arrive as Waspinator realises Blackarachnia used him and attacks her, the transwarp energy inside him going critical. Though the Primes refuse to let her go again, Blackarachina sacrifices herself by covering herself and Waspinator in a web cocoon so the blast can effect only them while the ensuing explosion takes out a chunk of Dinobot Island.
A crazed Wasp finds his way to Earth to exact his revenge on Bumblebee... but he doesn't count on the Elite Guard following him. When Wasp swaps bodies with Bumblebee, Bumblebee must try to convince the Autobots and the Elite Guard who he is. At the same time, Optimus Prime tries to convince Sentinel that Longarm Prime is actually the Decepticon Shockwave. In the end, it is revealed that Shockwave severely wounded Ultra Magnus in an attempt to make sure his identity as a Decepticon spy doesn't get revealed.
Unaware that he is being followed by the Elite Guard, Wasp heads to Earth to take his revenge on Bumblebee.
Bulkhead must face off against the Constructicons and their new leader, Dirt Boss, when they decide to hold the city's oil supply hostage. Meanwhile, the other Autobots manage to capture Lugnut, but find hauling him away a more difficult task.