Watch Optimus Prime Unleash His Rage in Thrilling New ‘Transformers: The Last Knight’ Trailer

When good Autobots go bad.

Sure, he’s all metal and machinery, but Optimus Prime has been the heart and soul of the Transformers series for four installments.

That heart appears to have gone cold in the upcoming fifth go-around, Transformers: The Last Knight.

The trailer shows the previously valiant Optimus going rogue, waging a war against mankind, with which he was previously aligned. “For my world to live, yours must die,” he says, before unleashing chaos on Michael Bay‘s world of explosions and giant robot fights.

In one thrilling spectacle, Optimus battles it out with Bumblebee and Mark Wahlberg. And Optimus appears to be on the winning side of the fight.

We may see why this good Autobot went so bad. The trailer ventures into the origins of the Autobots, in the medieval era, and the genesis of Optimus Prime himself.

“It started as a legend, one of the greatest of all. A thousand years we kept it hidden from what was destined to arrive,” Anthony Hopkins’ erudite character Sir Edmund Burton says.

Transformers: The Last Knight hits theaters on October 15.