“Editing is kind of a compulsion,” two-time Oscar nominee Joe Walker says. “I’m happy when I’m working.”  Certainly, looking at the work the editor has put in over the past 10 years, it’s easy to understand why that is. Of all the industry’s craftsmen and women, Walker has had one of the most admirable track records, comprised of collaborations with Michael Mann (Blackhat), Denis Villeneuve (SicarioArrivalBlade Runner 2049) and Steve McQueen. After cutting Hunger and Shame for the latter director, Walker worked on 12 Years a Slave, watching as the director made history, by becoming the first black filmmaker to win Best Picture. And this year, the pair follow up that 2013 outing with Widows, the most commercially-oriented of McQueen’s films to date.

A fresh take on a familiar genre, the heist thriller is adapted from an ’80s television series of the same name, created by Lynda La Plante. It follows four women who are left reeling in the wake of their criminal husbands’ joint demise. Struggling to make ends meet without their ill-gotten funds, the Chicago quartet turn to a criminal life themselves, attempting the heist their husbands never brought to fruition.

This week on Production Value, Walker discusses the challenge of the editor’s craft, which manifests in one particular scene from his latest film, involving a joke about guns. “For about three screenings, the only other person in the audience I heard laughing was Steve—nobody found it funny. Then, one day, we came back to the cutting room and said, ‘You and I think it’s great, but let’s try a more crude way to tell this joke,'” the editor recalls. Cutting a line in half and infusing the scene with musical intensity, Walker arrived at “a very tightly precise, rhythmic rendition of a joke,” resulting in a scene that worked. “There are 10,000 of those [moments] in a film, that you just try to deliver perfectly,” the editor notes.

For Walker, Widows presented two particularly interesting aspects on the editorial side, one being the size of its cast. There were 81 speaking parts, “and everybody [needed] their moment.” Another aspect to contemplate, in this case, was the use of VFX. “[It’s] a really interesting one because that’s the most recent development for editors, and that’s really substantially changed what you can do. From only 10 years ago, I was dropping only one optical effect into a film; now, on Blade Runner [2049], we had 1100 VFX shots,” the editor says. “It’s become very easy to really test what you want, and how it’s going to impact the story, so it’s become part of the way that I work now.”

Working throughout the edit with an “imaginary audience” in his head, Walker comes to understand what an audience will expect from any given moment, and can subsequently turn those expectations on their head. Watching Widows with an audience at the film’s Toronto premiere, Walker listened attentively to the crowd, to gauge how his work was playing. “There were moments where people gasped at the twists and turns of the story. It was very gratifying to me because all those moments are very carefully engineered,” he explains. “And I know that if a certain cut is a frame late, or the music doesn’t kick in with just the right volume, it doesn’t work as well.”

For more from our conversation with Walker—who will next take on Dune with Villeneuve—take a look above.