"Solo: A Star Wars Story" is the most action-packed Star Wars movie ever.

Seriously, Han Solo's origin story kicks off with one hell of a speeder chase and then continues to spoil the audience with set pieces for two hours. And one of the best sequences in the film (which the trailers have featured prominently) is a train heist -- Chewie and Han's first big job together as would-be smugglers moving over (and clinging to) an Imperial train know as The Conveyex.

And it's unlike any train heist you've ever seen, thanks to the fact that the cars on this train tilt and lean around the track -- a track that weaves around and through very snowy, very tall mountain peaks. Moviefone recently sat down with "Solo" writers (and father and son) Lawrence and Jonathan Kasdan to find out how they came with this all-timer for the franchise, which owe its origins to a very mundane activity.

MOVIEFONE: The scene everyone seemed to love the most at the screening was the train heist. Can you guys walk me through your process of locking in on that sequence?

Jonathan Kasdan: So, that process was lengthy, but here's the anecdote that's maybe worthy of repeating. I was on the treadmill, actually. Running. It was at the beginning of this process and I was listening to the artist Shooter Jennings -- who I'm a big fan of, and whose dad is also a legend. And he had a song come on called "Slow Train."

And I got a very vivid image in my head where I'd love to see Han be in a situation where he jumped onto the roof of a speeding train, and he did it right behind his mentor. I ran over to Larry and I said, "I've got this image. This is what it's going to be -- he jumps onto a speeding train." And Larry said, "Okay..." and that was not the reaction I was hoping for. I was like, "You don't realize? This is the movie." And he stopped and said, "What if the train twisted and flipped and titled?" And I said, "S**t. That's it."
That's such an inventive move. I've never seen that before.

It's so fun, you know? That sequence, the spirit of that sequence, remained true from that moment to the finished movie. And the events and the order of what happens in each thing was contributed to not only by every director, but by every concept artist, every pre-vis person, every special effects editor. We had [editor] Pietro Scalia, who is genius, and Chris Rouse came in and helped us for a bit, who was a screenwriter and editor on the Bourne movies. He came in and gave us a real help in those sequences. And those sequences wouldn't be what they were without all those people.

You can see the train heist in all its glory when "Solo" hits theaters Thursday night, May 24.