Voir Transformers Robots in Disguise, Vol. 2 - Episode 12

Though Optimus’ training in the Realm of the Primes is not complete, the Great Evil he’s been told of is approaching, and the Primes lend Optimus a fragment of their collected power before sending him to Earth to face it. Meanwhile, on Earth, Strongarm and Sideswipe are captured by Steeljaw’s Pack, but before the ‘Cons can do anything with their prisoners, the mysterious First Decepticon orders Steeljaw to begin construction of the gateway that will bring the master villain to Crown City from another dimension. Bumblebee and Drift set out to find their friends, and track them to the Crown City Colossus, where they find the Pack building the gateway. Optimus arrives at the Scrapyard, and speeds to locate Bumblebee, reaching the Colossus just as the gateway activates and MEGATRONUS comes to Earth.