If there's one scene we all remember from "The Divergent Series: Insurgent," it's Tris (Shailene Woodley), hooked up to a simulation under the watchful eye of the villainous Jeanine (Kate Winslet). Janine wants Tris to prove that she's 100 percent Divergent by passing simulations for each of the factions and opening a mysterious box, the contents of which could explain the world the ruined Chicago was before.

Tris is suspended from the ceiling, dangling from tubes and wires in the midst of a fear landscape. Suddenly, her eyes snap open and she bursts through the glass wall separating her from her observer, tackling Jeanine and propelling the both of them straight through a wall and into a hellish free-fall over a surreal city.

It's not real, but it sure looks cool.

In this exclusive behind the scenes featurette, check out footage of how, exactly, Woodley and Winslet pulled off that stunt. Mostly with green-screen and very, very precise movements.

Visual effects supervisor James Madigan explains in the featurette why it was important that Tris face the specific trials that she did.

"Everyone has these sort of feelings of insecurity when you have these falling dreams, when you're like, 'how did I get here and what am I going to do?'" he said. "It was about putting that on screen and having her entire world as we know it fall apart at the same time."

"The Divergent Series: Insurgent" is available on Digital HD July 21, and Blu-ray and DVD on August 4.