Warning: This article contains spoilers for the fourth and final season of Barry.

Bill Hader is planning to direct a horror movie after finishing up the last season of Barry. With terrifying sequences like Sally’s drunken PTSD hallucination, Hader is testing the waters of horror filmmaking in the final episodes of his HBO series. While doing the press rounds for season 4, Hader has teased two projects he’s developing as a potential follow-up to Barry. While one of these ideas is “kind of hard to describe,” the other one is a more tangible concept that has gotten fans excited. Hader describes it as “Barry-like in tone, but instead of a crime thing, it’s like a horror thing.”

Barry itself has veered closer and closer into horror territory as the seasons have gone on. It started out as an offbeat crime story about a hitman who wants to become an actor, but it has since morphed into a psychological thriller about an unhinged serial killer doing the mental gymnastics (and podcast consumption) required to justify his murders as an act of God. After Barry snapped with the monastery massacre in the season 2 finale, this already very dark show got even darker. Following this shocking midpoint twist, Barry left behind its roots as a crime caper and descended into grisly, unsettling horror. Season 3 introduced psychological warfare, a man-eating panther, and a haunting vision of the afterlife. Season 4 has gone even further down the horror rabbit hole with a mysterious knock at the door in the middle of the night and a shadowy figure following Sally around to visualize her trauma.

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Hader has directed episodes of all the previous seasons, but in the show’s fourth and final season, for the first time in Barry’s run, Hader has directed every single episode, and he’s skewed closer to the horror genre than ever before. As he gears up to make his feature-length directorial debut with a horror movie, Hader seems to have treated the final season of Barry as a sort of trial run before becoming a full-blown horror filmmaker.

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Every previous season of Barry featured a different kind of cinematic cutaway. The first season had idealized fantasies of Barry’s future, the second season had flashbacks to the most harrowing moments from Barry’s past, and the third season had sinister hallucinations to show Barry’s fragile psyche finally starting to crack. As it wraps up the series, the fourth season has unified these cutaway styles with a gonzo mix of all three; a flashback to Barry’s childhood will morph into a fantasy of a wedding, which will morph into some disturbing nightmare.

By far the creepiest aspect of Barry season 4 has been the ways that Sally’s PTSD is manifesting itself. After killing a biker in self-defense in the season 3 finale, Sally has been continually haunted by the guilt and trauma surrounding the event throughout season 4. The biker could be spotted sitting at the back of her acting class. In one particularly horrifying moment that evoked the feel of a David Lynch film, Sally sat on a plane and a child’s giggling could be heard as the reanimated corpse of the man she killed leered over the back of the seat in front of her.

These hallucinations came to a head in the sixth episode of season 4, “the wizard,” when Barry left Sally alone with their son John at their little house in the middle of nowhere. Her worsening depression and isolation caused her to spiral. She spiked John’s drink with alcohol to make him pass out, then drank herself into a stupor and collapsed onto her bed. That’s when she started hearing a male voice shouting from outside, threatening to come into the house and attack Sally and her son. What follows is arguably the most terrifying sequence in the entire series.

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As Sally goes over to the front door to see if there’s really an intruder or she’s just imagining one, a slender figure dressed in a full black bodysuit creeps up behind her and follows her back into the bedroom, where it slams the door and then magically vanishes into the living room. Audio from Sally’s season 3 manslaughter is heard as Sally desperately tries to open the door to save John from an assailant who might not even be real. Then, a truck crashes into the house and tips it on its side. This whole ominous scene keeps the audience on the edge of their seat because they have no idea what’s going on. It’s unclear how much is real and how much Sally is imagining. When John finally awakens to find the house in disarray and Sally on the phone begging Barry to come home, it seems to confirm that the attack was imagined and Sally simply got drunk and trashed the house – but even that’s uncertain. One thing is crystal clear: Sally is losing her mind, and that’s the point of the scene.

A horror movie might seem like a radical left turn to audiences who know Hader as one of Saturday Night Live’s most gifted impressionists, but a lot of comedians have been dabbling in horror lately. Jordan Peele directed Get Out, Danny McBride worked on the new Halloween trilogy, and Chris Rock starred in Spiral: From the Book of Saw. The two genres aren’t as different as they seem; horror and comedy are two sides of the same coin. They’re both driven by the creators’ instincts, they’re all about timing, and the goal with both comedy and horror is to lead the audience to expect one thing, then surprise them with something they’re not expecting.

If Barry is Hader’s calling card as a horror director, then horror fans are in for a doozy when he sets up his first feature film. He knows how to use mind-bending visuals to create a feeling of unease and he knows how to draw his audience to the edge of their seat, subvert their expectations at every turn, and bowl them over with regular plot twists. He’s proven that he’s a master of unnerving imagery, a master of creating a spine-chilling atmosphere, and a master of telling stories with just enough ambiguity to spook audiences long after the end credits have rolled.

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