After defeating the Terracons and losing the key to their getting home planet forever Optimus Prime had sent the auto bots on small incognito missions.

He sits in an large old warehouse out of human sight. Where he Can finally reflect on the past and possible future. “Hmm…..” he says closing his eyes in thought.

He believed he was in peace, that is until you arrived finished with you mission before Bumblebee, Arcee, or Mirage.