1968's Hour of the Wolf has perhaps the single least-enviable position of any title in Ingmar Bergman's filmography: it's the feature film he made next after Persona. Anything would seem like a step down in ambition and visionary madness compared to that movie, though Hour of the Wolf makes a good-faith effort to stand out in its own right. Famously, this is Bergman's horror movie, though declaring it such, I think, diminishes how much horror had crept into several of his earlier films. The death-obsessed atmosphere of The Seventh Seal; the surrealist nightmare that kicks off Wild Strawberries; the slasher-movie violence of The Virgin Spring; the unspeakable spider-god of Through a Glass Darkly; the dusky unreality and instability of Persona itself; if none of these quite meet the "ghosts in a haunted forest" definition of horror, at least all of them have something of horror about them, above and beyond how much Bergman's '60s work had really leaned into the "dread" half of "existential dread".

Admittedly, Hour of the Wolf actually does have ghosts in a haunted forest: calling it "horror" isn't just some critical in-joke where we've all agreed to pretend that this chilly psychologically-oriented chamber drama is a genre film on the grounds that it's scary to be depressed. It's kind of even pretty good at horror, though of course it's still primarily a chamber drama, and it's using horror not as a way of scaring us in the audience (I have a hard time imagining a viewer sensitive enough to actually be scared by any of this while also being patient enough to deal with how glacially slowly the scares unfold), but as a tool for exploring the profound terror felt by one Johan Borg (Max von Sydow), a painter who has returned to Baltrum, one of the East Frisian islands off the northwest coast of Germany, with his pregnant wife Alma (Liv Ullmann). Johan is suffering from insomnia, accompanied by visions of terrifying demon-like beings; as we'll learn, watching him alongside Alma, he's being literally haunted by feelings of guilt and suppressed desires.

The story of Hour of the Wolf is a relatively straightforward matter of secrets being revealed over the course of several sleepness nights, as Alma tries to offer support to Johan without having the least idea if she can, or if she should, and without knowing whether she and her unborn child are better or worse off for being so intimately tied together with a man losing his tether on reality. There are multiple dinners at the local manor, where people from Johan's past reveal some truths he'd rather not have revealed and Alma would rather not have heard, especially about his ex-lover Veronica Vogler (Ingrid Thulin - the first time that she's not playing a dowdy, sexless figure in a Bergman film), one of the apparitions he's been seeing in his visions.

What makes it less straightforward is the way the film works us into this narrative: it offers no fewer than three different layers of external framing to dig through. First, the film presents a quick bit of exposition in white type on black with a first-person note from the filmmaker (who is not, necessarily, the same as Ingmar Bergman) explaining how he came into the knowledge to share this very horrible true story with us. And then the text shifts to the usual Bergman movie font for the opening credits, the thin, sleek lettering feeling all the more stately after that clunky typewriter face. As the credits play out, we hear the sound of a busy film set preparing a shot, inside a studio. And then thee noise dies down just in time for the credits to end, at which point the action cuts to a medium shot of Alma leaning against a fence in front of the cottage where the action will unfurl. And she talks right to us, staring right into the camera. But it's not us-us. She's talking to the filmmaker, explaining that since she already gave him her diary, she's not sure what more use her spoken recollection will be.

I would be hard-pressed to explain why this little nothing of an opening so thoroughly discomfits me, and I'd probably sound like a lunatic if I tried. Suffice it to say that there's a lot of instability, just between that opening card describing the project, and the sound of a film set playing in the empty invisible void during the credits. It immediately raises questions the film has no plans to answer about how much of what we're about to watch is real and how much of it is the constructed fiction of filmmakers, and this is all the simple part compared to the completely baffling and disorienting opening shot. The shot doesn't work - by which I mean, it works almost too well to handle, but it doesn't work according to the rules of cinema. The effect of having an actor stare directly into the lens and talk to us is one of the most powerful gestures a filmmaker can employ, as the director and co-star of Persona knew very well. But this is doing something different than anything in that film, because she's not really addressing us: she's talking to the director. And this is something that we see in documentaries, though fewer documentaries in 1968 than now. And even then, the talking head isn't generally talking to us, they're talking a few inches to the left of the lens, comfortably preserving the fourth wall. Besides, this plainly isn't a shot from a documentary: the aesthetic style is too pronounced, and Alma isn't talking the way you'd talk to a man with a movie camera; she's talking to a person's face, it just so happens that the camera and therefore the audience is occupying the space of that person.

This, anyway, is the opening gambit of Bergman's "horror film": a successful attempt to unsettle the viewer's relationship to the machinery of cinema that follows pretty nicely from the deconstruction of the medium that took place in Persona. It's less complicated and robust here; this is, after all, just a genre picture, not an avant-garde art house epic. But it's still a hell of a bizarre way to start things out, and it makes Hour of the Wolf a strange and distant object, insisting on its artifice while in the same moment attesting to the authenticity and reality of its content.

If all this did was to continue Bergman's short but focused period of experimenting with how movies communicate meaning, I'd still enjoy it, but it's also doing work in connection to the story that the film is telling, once we've dug all the way through the different framing devices. Hour of the Wolf is about the uncertain boundaries between the world as it is and the world as we perceive it, with its title reflecting the deep hours of night between midnight and the first tendrils of dawn. It's a time when the distance between what we think we see and what's actually there is most tenuous and uncertain, a time when, for example, a man who is being haunted by visions of the things he regrets from his past might be especially hard-pressed to mark a clear distinction between reality and his increasingly crushing, angry memories, to such a strong degree that maybe he might even start infecting his wife with those same memories. Or perhaps this is all real, and the man is in mortal danger as a result of all the wrong-headed choices he made in his life.

This is not by any means a new metaphor for a ghost story to plunge into, and it wasn't in 1968 either. Nor is it new that Hour of the Wolf deliberately muddies the distinction between what's real and what Johan perceives. What does set the film apart is the means by which it does this, and how intensely. Most horror films asking us to look inside the fracturing psyche of their main character do not, after all, do so while also using the film itself as a large-scale attempt to make the same blurry lack of distinction between reality and overheated fiction. And even more so, most horror films - most films of any sort, don't do all of this with the extraordinary focus on the human face as a canvas for feelings and unexpressed thoughts that we see here. Bergman had been steadily refining his use of close-ups for years, but Persona made a massive leap forward in his experimentation, turning the close-up into something so purely expressionistic it almost starts to become unrecognisable as a human face. Hour of the Wolf backs down from there - Johan and Alma's faces are never transformed into a single hybrid face, more's the pity - but its faith in the ability of actors to do great, imposing work in crafting characters through the smallest gesture is still miles beyond anything else I can name in any "horror movie", past, present, or future.

There's one obvious way this plays out, but I'd like to stop on the less-obvious ways first. One of the very cunning things Bergman and cinematographer Sven Nykvist do here is to use close-ups to do the work of genre; the film has its fair share of inky black nighttime locations, but what's interesting about them here is not how the blackness creates a sense of unknowable forboding, a sense that anything can be hiding in the dark (which is how most horror films, including very great ones, would do it), but how Nykvist carves von Sydow and Ullmann's faces out of the black, making them curving lines of light and text wrenched out of the imposing, cruel dark of the background. The effect, particularly in the big conversation where the film's title is sussed out and its implications considered, wonderfully suggests the conflict between the self and the terrifying mystery of the night that is, in its way, the emotional core of the film.

Less showily, but no less effective, is the way the filmmakers use close-ups to expose their monsters. The film is light on actual "scares", but not devoid of them, and they gain impact from being seen up close and personal, with the suggestion (and later the direct statement), that smiling human faces can be just a guise for devouring evil - take that for as much of a metaphor as you like - and this is helped along by much these demonic visages fill the frame. This is especially well-used in the case of Erland Josephson, a multitalented artist who had popped up in this or that Bergman film but never given a msjor role, I imagine because he wasn't really first and foremost an actor at this point. His part in Hour of the Wolf isn't really major, either, but one can almost hear the lightbulb switch on as Bergman figures out what he can extract from Josephson's face:  a haughty leer that feels carved out of stone, which when shot from a slightly low angle ends up being the most menacing, malicious element of the movie. Josephson's patrician air would very shortly start yielding great things in Bergman films, and while I don't think Hour of the Wolf quite gets us to the point that Josephson becomes a crucial member of the Bergman stock company (the last member to join that group), it is the film where one can almost see Bergman starting to discover what a resource he's been sleeping on in this actor's well-worn face.

I said there was something especially obvious, though, and her name is Liv Ullmann. The Bergman/Ullmann collaboration, which included but lasted beyond the last great extramarital love affair of the director's life, is one of cinema's most legendary, and deservedly so: out of ten collaborations, only one resulted in a performance that's any less than great, and that's only because 1977's The Serpent's Egg was such a deeply misconceived project in the first place. Their first collaboration was Persona, and there's a strong argument it's the best (there's also a strong argument, I think, that Ullmann's work in Persona is the all-time highlight of cinema acting, but let's leave that alone), but it also feels different from the rest: partially because she only says one word, partially because the whole movie is so damn weird about how it conceives of its characters. Hour of the Wolf is the first time that it seems that Bergman and Ullmann are really feeling each other out, and the first time we see exactly what she can do under his direction. My understanding is that Swedish audiences tend to like Ullmann's performances less than the rest of the world on the grounds that she never shook her Norwegian accent, and I think I can hear it, a little bit: her cadences are different than the rest of the cast, and maybe she's slightly flatter in her vocal tonality. Still, if that's true, in this film, at least, it's worth it. It gives her a sense of being in the wrong place, a location and maybe a marriage where she never should have been, an alien in a world that's already foreign to human emotions.

There's more to it than just her vocal performance, though. Hour of the Wolf is, when we get to the bottom of it, a film about Alma, not about Johan: the opening and closing addresses to the audience would make that clear enough, even if the rest of the film wasn't constantly affirming that the most troubling aspect of his descent into madness is how it affects her, and that the real terror isn't the demons of one's own past, but being confronted with the discovery that a trusted loved one has depths and layers that are simply too troubling and horrible to simply wave away as part of he past. Accordingly, while the film benefits from von Sydow's tormented performance, it depends on Ullmann's careful management of Alma's concern, worry, motherliness, and fear for her own safety. And again, this is mostly done through close-ups, or things like that opening medium shot (which feels, in context, a little bit like an advertisement for some of the small-scale pyrotechnics that Ullmann will be setting off later in the film), where we simply hold on her and see what she does in a protracted moment of emptiness. Almost all the time, it's something extraordinary, and while she's willing and able to put the most obvious read on a moment where Alma needs to be doubtful, or terrified, often Ullmann instead beings in curiosity, annoyance, or the impression that she understands more than Johan does about what he's saying and what's happening, often cutting against the grain of the script in a way that accentuates and deepens what was already there.

She's hemmed in a bit by the needs of the genre, and the fact that her character is basically standing the side of the entire plot, watching it from a relatively safe distance, but it's still a powerhouse performance, and while I think I would love any version of Hour of the Wolf, the one with Ullmann in the lead is a genuinely great film that certainly deserves to be counted as top-tier Bergman, or at least near the top of the second tier. Her work adds a note of wise melancholy to what would otherwise be a straightforward (though excellent) study of how isolation and psychological instability work together, and it's no surprise that Bergman decided to follow this up in later films: Hour of the Wolf ended up kicking off an informal trilogy of Ullmann/von Sydow marital dramas built around genre and location. But even without bringing those into the equation, what this film, and those two performers, have already told us about the terrifying aspects of binding your life to another person's makes this an exceptional work, and maybe the closest thing that there is to an underrated Bergman film from the 1960s.