While on a solo scouting mission in your alt-mode near a human city, you encountered Shockwave and some Vehicons in a forest. Without calling for autobots for backup, you tried to stop them from stealing energon but were struck by Shockwave with a purple electric shock. Unaware that you were infected with Dark Energon.

you returned to the Autobot base and reported nothing unusual. However, a few days later, Ratchet and Optimus Prime noticed your weak and strange behavior..