Joel Negron cut Project Hail Mary from 700 hours of footage into a 2.5-hour film

Cutting a movie is hard. Cutting a movie where your lead actor is in every single scene, and his co-star is a spider rock crab with no arms, no face and no mouth, is a different kind of hard. That was the job facing Project Hail Mary editor Joel Negron, who had 700 hours of footage - nearly 29 days' worth - to turn into a 2.5-hour film.

"The film that I got was an embarrassment of riches. There was a lot of good film, and that's what made it challenging," Negron said during a panel at Deadline's Contenders Film Los Angeles event. "There was so much good film to pick and choose from."

The adaptation of Andy Weir's bestselling novel stars Ryan Gosling as Ryland Grace, a middle school science teacher who wakes up on a spaceship with no memory and has to save the sun from dying. Gosling, Negron noted, is in every scene - "which is crazy, and he was there every day they were shooting."

Finding the emotion in a crab that can't talk

The bigger puzzle was Rocky, the sentient alien Grace befriends in deep space. Screenwriter Drew Goddard describes him as a "spider rock crab who can't talk," brought to life by puppeteer and voice actor James Ortiz.

"The other challenge was finding the pieces of Rocky, because he's got no arms, no face, no mouth," Negron said. "You have to find the emotions of Rocky." Directors Phil Lord and Christopher Miller kept pushing him to "find the emotional bits" and "the funny bits" - mining miles of footage for the best takes.

Miller summed up what the film is really about: "We really wanted it to feel like it had the big scope and scale that you want to go to the movies for, but the heart of it is a story about two beings who are super different from one another."

Two beings who don't speak the same language, but solve a huge problem together through empathy and trust. That's the scene Negron spent 700 hours trying to get right.