Based on the George Polk Award-winning New Yorker article of the same name, director Edward Zwick’s Trial by Fire chronicles the wrongful 2004 execution of Cameron Todd Willingham (played by Jack O’Connell).

Willingham was convicted of the murder of his three young daughters, who were killed when a fire swept through his Corsicana, Texas home overnight, less than two days before Christmas in 1991. Recreating the fire for film became Zwick’s biggest on-set challenge: Only a precisely calibrated synthesis of controlled real-life burns and digital superimpositions would pull it off. Here Zwick reveals how he struck this balance, and why he slated this high production hurdle at the very beginning of the shoot.

Day 1

Skip Cosper, who was my first AD on several movies—a very experienced man who fought in Vietnam—has an expression that goes, “No plan survives contact with the enemy.” In this case, our enemy is production.

Visualizing the decisions you’ll have to make on set is in infinitely harder than making them. You have to stretch the limits of your imagination and your storytelling before you show up, and pre-production gave us the benefit of time to do that. But whenever you start shooting, you never find anything as you had planned it. It may take way too long to complete an important take and we may have to find a shortcut. Now that we’re on set, there’s just no time to fuck around—especially on a low-budget movie like this.

Day 2

It’s always best to start with the hardest days. Once we get further into production, we’ll have less and less time to do the things we initially put off, so a battle, chase, crash—or in our case, re—scene is almost always best to do before everything else. Shooting the fire today made for an interesting challenge. The sequence involved a great deal of planning by cinematographer John Guleserian, visual effect supervisor Alan Munro, and me. We’ve all done big action scenes—a certain amount of explosions, or work with fire in some way. But it was clear from the beginning that in the little house we filmed, in which there were kids and our entire crew, the use of real fire would not only be time-consuming, but dangerous. Ironically, we’d never be able to capture the intimacy and horror of what a fire raging through a small space like that would be with actual fire.

Fired Up: Director Edward Zwick (R) and star Laura Dern (L) went in guns blazing to shoot Trial by Fire‘s most elaborate sequences. Photograph by Steve Dietel

Fire is one of the last two frontiers of visual effects, the other being water. Life of Pi was the game-changer when it comes to water VFX—a triumph, though that was started by what Peter Weir did with tanks for Master and Commander: The Far Side of the World. Fire, however, remains the final holdout. Explosions were the first fire VFX that crews had to deal with and now we see them in every movie; they’ve gotten so big that they’ve become kind of silly. But there are now quite a few digital techniques to give it a feeling of realism. One way is to take real fire and digitally cruise it into the proximity of the actors. To that end, our process was two-fold: It involved lots of rehearsal and takes of Jack O’Connell stumbling through that house, and then recreating the fire later on a separate set.

We took a Rashomon approach to Jack’s Cameron Todd Willingham character, shooting the fire scene three different ways to depict three different versions of its events. In one version, he’s heroic, in another he’s a neutral force, and the third shows his fear, inability, and reluctance to do what he needs to do in the moment. This called for me to direct it in three different ways, in terms of camera angles, movements, and intensity. Alan, who is a director himself, bore with me as we shot scenes with Jack without any fire. That way, we’ll know what to watch out for when it comes time to add real and digital superimpositions later on.

Day 8

Today we created a “burn set”—a facsimile of key areas of our house location. We built it in the yard of an abandoned prison, where we did controlled burns and photographed hundreds of little things moving and burning from all sorts of perspectives for coverage. We knew what to capture because we’d already rehearsed the path our actors would take through the house.

But that wasn’t enough: What truly made this scene work was interactive light. An onscreen fire not only needs to look like a real fire, but you need to see its effects on the characters in the scene. To that end, John, who’s a very technically adroit DP, decided to put little strips of LED lights on the wall and on objects. These strips were wired back to someone working behind a dimming board, who could guide them up and down and oscillate them whenever we wanted. This created interactive light on our actor, so we were able to shoot the scene without any actual fire, and instead with other light sources. There was also the question of believability in Jack’s performance. To that end, we dropped some objects on him from the ceiling, to capture his reactions to them. We also knocked over a dresser in front of him so he could react to it, as opposed to having him do green screen acting. Later, we’ll replace those objects with the flaming objects we’ve already shot.

You always want to shoot as much as you can in sequence. There are a lot of things in Trial by Fire that we won’t be able to shoot in sequence, but the ones we can will probably be the most successful. We shot the fire and Jack’s relationship to his children early on precisely for this reason. You can rely on rehearsal, your actors, or special effects, but that experiential feeling of something happening for the first time… you can’t capture that more than once. MM

— As told to Ryan Coleman

Trial by Fire opens May 17, 2019, courtesy of Roadside Attractions. All images courtesy of Roadside Attractions. This article appears in MovieMaker’s Spring 2019 issue.