Forced by circumstances into a desperate gambit, Optimus Primal takes the Spark of the greatest of his Autobot ancestors into his body. While the Maximal crew works feverishly to repair the destroyed circuitry of Optimus Prime and end the timestorm that threatens to tear their universe apart, their leader struggles to stay alive. His body is wracked by the strain of containing two Sparks - something his bio-mechanical battle frame was never built for.
By the time the Spark of the Autobot leader is returned to its rightful place, Optimus Primal has been mutated by its power into Optimal Optimus, a Maximal of incredible size and astounding might. Armored and equipped like an Autobot warrior from the Golden Age of Cybertron, he casts a formidable shadow, and presents the greatest threat Megatron and his Predacons have ever faced.