Inventing time-travel isn't easy. It requires brains, technical know-how, a heavily-modified DeLorean and, last but certainly not least, a whole lot of weapons-grade plutonium.

It's that last piece of the puzzle that lands Dr. Emmet Brown in hot water in the original Back to the Future. Just as Doc Brown and Marty McFly prepare to attempt time travel for the first time, a VW bus of armed Libyan terrorists appear and start shooting up the place.

What exactly did the Doc do to cross the terrorist cell? Did he promise to make them a bomb? How did he escape from them to begin with? How did they track him down? Just how exactly did he manage to steal all that plutonium in the first place? That's what this fan-made trailer that serves as a prequel to Back to the Future looks to explain.

It's called "1.21 Gigawatts," and it's all kinds of intense. Using clips from Back to the Future, My Favorite Martian, Camp Nowhere, Things to Do in Denver When You're Dead, Dennis the Menace, Zero Dark Thirty, Argo, The Sum of All Fears, Syriana, Iron Man, Dazed and Confused and Munich, Tyler Hopkins has put together a trailer for a film that we will sadly never see made.

Back to the Future co-writer and co-producer Bob Gale said back in 2014 that fans shouldn't expect new Back to the Future films or re-releases of the originals.

"Let's face it, we've seen a lot of sequels that are made years and years later and I don't think I can name one that's any good, that lives up to the originals," Gale said. "I don't think you can recapture it."

This is probably true. Then again, Gale probably hadn't cooked up an idea like the one featured in this fan-trailer, where it appears Doc Brown promises to build a bomb for terrorists, is hunted by the U.S. government and is involved in some serious criminal activity. We all knew Doc was crazy, but this trailer shows just how far he was willing to go to make his dream of time-travel a reality.

You can watch the full trailer below.

Back to the Future Prequel Trailer: 1.21 Gigawatts from Tyler Hopkins on Vimeo.