Joseph Gordon-Levitt found his new thriller 7500 his “most challenging acting job” ever because it was such an immersive experience.

The Inception actor stars as Tobias Ellis, a first officer who has to fend off hijackers and take back control of his plane during a flight from Paris to Berlin.

Gordon-Levitt returned to acting after a three-year hiatus to film Patrick Vollrath’s directorial debut, which is set almost entirely in the plane’s cockpit, and he admitted the experience was tough because Vollrath has an immersive way of filmmaking.

“I don’t think it’s an exaggeration to say that this movie was the most challenging acting job I’ve ever done. I know that’s quite a statement. I’ve done a lot of acting jobs in my life, but it really was,” he confessed to Variety. “(Patrick’s) approach is all about immersion. He gears his shooting style to let the actor immerse themselves in the characters and in the story.”

He explained that Vollrath devises his set so his actors just have to focus on acting rather than worrying about technical factors such as lighting and standing in the right place, also known as hitting their marks.

“Patrick’s approach to filmmaking is all about stripping those technical elements away, so we’re not hitting our marks,” he stated. “There are no marks. The whole set is lit. You can move anywhere at any time. The camera is hand held. There was a script, but we only used it as a springboard. Instead the camera would just roll for 20 minutes, 30 minutes, 40 minutes at a time. He would just let us be in that situation.

“Combining that intensity with the extremely realism we were hoping to achieve meant that I was subjecting myself to some really powerful and brutal feelings and emotions and experiences.”

7500 is now streaming on Amazon Prime Video.