See what happened before Optimus Prime and Megatron came to Earth.
On their home planet of Cybertron, the Autobots and Decepticons are involved in an explosive battle over the coveted AllSpark. With the fate of the universe at stake, the Autobots send it far from the reaches of the ruthless Megatron, leader of the Decepticons. But there are even more surprises in store when it crash-lands on Earth.
22 mins
