The Rebirth
S4, E2: While Optimus Prime tries to figure out where his team and the Cybertron plasma chamber key have gone, the Autobots on the planet Nebulos team up with a rebel group to defeat the evil Hive.

S4, E2: While Optimus Prime tries to figure out where his team and the Cybertron plasma chamber key have gone, the Autobots on the planet Nebulos team up with a rebel group to defeat the evil Hive.