Warning: Despite its highbrow imprimatur, the video below is extremely explicit. We cannot overstate this: It is literally a clip from a porno movie. So don’t watch it if you’re at work, at Starbucks, or any other place where such a thing might be frowned upon. At the very least, put on some headphones.

Josh Karp’s new book, Orson Welles’s Last Movie: The Making of The Other Side of the Wind — written up recently in these pages — contains a marvelous, little-known story about the legendary filmmaker’s involvement in a high-end mid-1970s pornographic film. Welles, wrote Karp, “wound up editing a hard-core lesbian shower scene that he couldn’t resist cutting in Wellesian fashion with low camera angles and other trademark flair.”

News of Welles’s role in the movie, called 3 A.M. (or 3 A.M.: The Time of Sexuality), was actually broken in 1977, when Joseph McBride, the eminent film historian, wrote about it in What Ever Happened to Orson Welles?. But this was news to me. Exciting news! Historians, it’s fair to say, probably won’t unearth adult films cut by Michael Curtiz, Erich von Stroheim, or Satyajit Ray. Truly, this was a sui generis collaboration of high and low culture.

3 A.M. was directed by Gary Graver, Welles’s cinematographer on The Other Side of the Wind. (The productions have several crew members in common.) It is the gloomy story of a dysfunctional family: Elaine and Mark are married with two kids, and share their California home with Elaine’s sister, Kate — played by Georgina Spelvin, who appeared in 1973’s classic Devil and Miss Jones. The opening minutes, suffused with a great deal of moaning, are a vivid demonstration of Mark and Elaine‘s healthy sex life. I don’t want to spoil the plot, but everyone gets laid, including the kids and a nosy neighbor.

Welles’s presence in the editing suite was owed to his own impatience. He’d been working with Graver on The Other Side of the Wind, his unfinished project shot over seven years. Alas, Welles didn’t have the budget to pay the crew. To offset this volunteerism, Graver, who had a family to provide for, worked on erotic films. As McBride wrote, Welles in turn …

… reciprocated by working without credit on one of Graver’s hard-core films, 3 A.M. Fuming that Graver was busy editing it instead of working on his projects, Welles volunteered to cut a sequence to speed the film’s completion. The star of 3 A.M., Georgina Spelvin, proudly told me that Welles was responsible for the dynamic editing of her masturbation scene in a shower…

Porn was a departure for Welles, who was not inclined to depict sex in his own films. The problem, he told David Frost in 1970, was that “ecstasy … is not to be communicated by a couple of people, or one person, or any combinations there of, unless it’s actually happening … [Ecstasy] is really not part of the thing we can do on celluloid.”

3 A.M., for which Graver adopted the pseudonym Robert McCallum, is nicely shot, narratively compelling, and filthy. (A resourceful friend supplied Vulture with a pristine copy.) The shower scene, which can be seen below, occurs around the 29-minute mark. Kate, naked but for a yellow towel on her head, enters the shower. She hears a knock on the bathroom door and, presuming it’s her niece, makes welcoming noises. “Excuse me,” says a brunette dressed in jeans and a skimpy white shirt, “may I use your telephone?” Girl in Shower, as she’s called in the credits, closes the door. “I don’t know who she was, or where she’d come from,” says Kate in voice-over, as her guest removes her clothing, “but she was suddenly upon me and I loved it.”

Indeed. There are a couple of brief overhead shots, then a tight shot of the kissing, groping women. The camera settles on them, trails down their bodies, then cuts to Kate gripping the top of the glass shower. The women have sex for nearly seven minutes, in positions that, given the space, are impressive. There’s no masturbation that I’m aware of — maybe I missed it in all the excitement — but there’s definitely a prominent low-angle shot about 31 minutes in, filmed from outside the glass shower, of Girl in Shower digitally stimulating Kate.

To my untrained eye and ear, the scene is reasonably Wellesian. There’s the low-angle shot, which is reminiscent of famous predecessors in Citizen Kane, Touch of Evil, and The Lady From Shanghai. And there’s the moaning on the soundtrack, which harks back to the famous battle sequence in Chimes at Midnight. But here’s Vulture’s Bilge Ebiri for a more informed take:

I guess I should first offer the caveat that I’m not exactly all that familiar with ‘60s and ‘70s porn, so I can’t tell how different this is from other scenes in other movies that might have been out around this time. But the scene does stand out from what I’ve seen of the rest of the film. For starters, it’s longer than one expects. And the editing choices are actually kind of creative — we focus on details that might not necessarily be the “sexiest” choices, but still feel quite effective. For example, the woman sucking her own toe in ecstasy, or a couple of the furtive glances between the two — it’s actually kind of touching. The high angle is great, and has been deemed “Wellesian,” but really, if you’ve got a lesbian scene in a narrow shower, and your two leads are groping around on the floor, chances are you’re going to have a high angle or two. It feels pretty functional here. Plus of course Welles didn’t shoot the film — Graver did. As for how it compares to other work deemed “Wellesian”… Welles’s cutting in the ‘60s and ‘70s tended to be kind of frenetic, and this is actually less frenetic than one might have expected. But then again, why should he go experimental with a porn film that doesn’t bear his name? It’s odd. The sex scene in The Other Side of the Wind — at least the one with footage that’s been made available to us — is supposed to be fast and wild and experimental and crazy. But that’s also supposed to be a film-within-a-film, and he’s actually consciously mocking that style. Sex isn’t something we see much of in Welles — in part because he was making films during the studio era and, even though he was outside of the studio system after a certain point, he probably still had to stick by Production Code demands. But I guess the thing that most distinguishes this scene might be most “Wellesian” thing about it: It’s a nice scene. Even almost kind of (gasp) moving. He did a good job.

The film is terribly well made. (Many of Graver’s hard-core films, Flavorwire noted recently, are considered classics.) 3 A.M. has the grainy, deep-hued look of McCabe & Mrs. Miller–era Altman. As for the shower scene, it’s disturbing and riveting, and this is surely owing, at least in part, to Welles.

“It’s absolutely true that he considered editing the essence of filmmaking. Welles would recreate everything in the editing room and put things together in new ways,” says Karp. It didn’t matter what he was working on. “He couldn’t resist doing it artistically.”

Sure, it’s a dirty movie. But it deserves a spot in the filmographies of both men. Graver was a tireless filmmaker. Aside from Welles, he worked with Roger Corman and John Cassavetes. He kept racking up credits, and spent the rest of his life trying to get The Other Side of the Wind funded, reportedly going so far as to approach Donald Trump. He was an artist. “Anyone who worked with Welles really loved movies and had a depth and affection for the medium,” says Karp. The Other Side of the Wind, which may finally be completed, was Graver’s white whale. “This was the film he’d thought would make his career.”

Here’s a clip of the Welles-edited scene from 3 A.M., with commentary from Ebiri: