Transformers: Energon Volume 1 (v. 1)

Ten years after Unicron attacked Cybertron, the planet is seemingly at peace, with most of the Decepticons absorbed into the community. However, Optimus Prime is still not happy, and fears another attack from Unicron. The High Council are skeptical of this. However, events soon lead Optimus to realize that not only is Unicron still functioning, but is on his way to a rich seam of Energon on Earth!