Be aware there are spoilers for In the Shadow of the Moon.

Where to begin with Netflix’s newest sci-fi thriller In the Shadow of the Moon, a time-travel film that tells a story in two directions, and begins with a glimpse of an ending that… doesn’t exist in the end? Got all that?

In the Shadow of the Moon is one heck of a plot-heavy mystery and a genre-bending detective thriller that sends Boyd Holbrook‘s officer Locke on a near-forty-year chase to hunt down a time-traveling serial killer. There’s a lot to dig into and fortunately, we had the chance to sit down with director Jim Mickle following the film’s Fantastic Fest debut to talk through some of the film’s biggest twists and turns. So with spoiler warnings officially out of the way, let’s dig into a full breakdown of exactly what went down in In the Shadow of the Moon, with some added insight from Mickle, from that evocative opening sequence to making sense of the twisty ending.

In the Shadow of the Moon opens on Philidelphia in 2024; an abandoned office building trembles and quakes while explosions and alarms rage outside. As the camera pans in to reveal a world on fire, a familiar but markedly different version of the American flag drifts through the flame. Then we jump back to 1988, where we meet Locke; an ambitious Philidelphia PD officer whose wife (Rachel Keller) is so pregnant she’s due any minute. That’s when he gets the call to report to the scene of the crime that will change the course of the rest of his life.

On an October night like any other, three seemingly unconnected people drop dead in gruesome fashion; hemorrhaging so profusely their brain spill out of their nose. When Locke discovers all the victims share the same puncture wound in their necks, it quickly leads him to the culprit — a young woman named Rya (Cleopatra Coleman), wearing a blue hoodie with an injured hand — who leads Locke on a foot chase down to the subway, where they have a chilling confrontation.

Somber and sad, Rya asks “Is this where it happens?” before congratulating Locke on the birth of his daughter and apologizing for his partner’s death. Thing is, his daughter hasn’t been born and his partner’s still alive. They have a fight and Rya gets the upper hand, handcuffing Locke to a bench, but not before he tazes her and she falls into an oncoming train, dying on the spot. Locke’s daughter is born that night, his wife dies in labor, and everything is normal if sad, until 9 years later when Rya’s killing spree inexplicably starts again. And again in 2006. And in 2015.

Against all scientific reason, Locke meets Rya every nine years after the night of her death, and she’s always the same age, always in that blue hoodie, when she returns to kill more people on her list. And unfortunately, one person who wasn’t; Locke’s partner. That answers her mysterious apology, and as for the wound on her hand? Lock gives that to her in 2006. Yep folks, we’ve got a time-traveler on our hands. Over the course of the decades, Locke becomes obsessed with the one killer he couldn’t catch, losing his job and eventually, his daughter, in his relentless drive to stop the time-traveling assassin no one believes in but him. Just like he did the night of his wife’s death, he chooses the job and the chase over family, every time.

Mickle explained,

“That’s exactly what I loved about it, was just this guy who just keeps making these just horrible decisions. Because he has this hunch about something, and thinks that it’s going to be able to undo something. Especially when you see him at the beginning and he’s like so bright-eyed and so loves his job and his life and what he’s going to go forward. And then this thing happens to him that completely shakes him and throws him off. I feel like he’s like those guys that start and they go to play minor league baseball and they’re on top of the world, and they get married and have a kid and they’re thinking this is great. And then they don’t make a team and all of a sudden they’re like 30 and have no education and no ability to live life and no financial means. And you’re just like, well now what? I kind of feel like he’s at that point in his life and he’s like, if I could just get my arm back, I can go back to being like that guy.”

Locke never gives up on his pursuit of getting back his dream life, and over the course of his investigation, he uncovers that the killings aren’t random, but tied to members of a burgeoning political hate group called the “Real America Movement”. In the end, Lock learns that Rya is systematically hunting down the leaders of the hate group to prevent the war-torn future we glimpsed in the film’s opening moments, using a high-tech poison injection that can be triggered from the future.

She explains that in 2024, when she was nine years old, “an ordinary man parked an ordinary truck full of explosives downtown and watched it explode. His attack was just the first. Eleven thousand people died the first morning. Millions more in the civil war that followed.” While Locke kept hunting the time-traveler in the hopes of fixing his past, she was fighting for the future.

What’s more. She’s his granddaughter, and in this dark future, he’s actually the one who encouraged her to take the job in the first place. And they’ve been meeting in reverse order. While Locke travels forward through time, she’s been going backward on a one-way trip. Their final meeting is her first stop, where she meets her grandfather on what is also the day of her birth.

For Mickle, that counter-arc dynamic and the opportunity to subvert romantic expectations was one of the most interesting parts of the script.

“Ultimately, her story is backward, his story is forward. So the first time that they meet, it’s his first time meeting her, it’s her fourth time meeting him. And by the end of the story, it’s his fourth time meeting her and it’s her first time meeting him… You’re always looking at story in terms of character arcs, and to look at it and say you have one character whose arc is actually going backward, sort of superimposed on top of it, that was actually the hook that got me. I think it’s really a love story between these two characters. You know, there’s a big romance angle obviously. Then you find out that they’re related. I thought that was really interesting to treat this sort of absurdity of the fact that he’s… It was almost like these people had this romance of these characters that meet, and then they sort of get torn apart and one has to go on a trip or something. Then they’re sort of pining for each other, and then they come back and I thought that was really fascinating. And then to sort of mix the arcs on top of each other, I thought was really interesting.”

So, how exactly does the time-travel work? In the Shadow of the Moon doesn’t give an Avengers: Endgame style breakdown of the rules, but there’s enough in there to make sense of it. Mickle explained they were cautious to walk the line with over-explaining, “At some point, you sort of have to say there’s a language out there for time travel and you’re either a part of that or you’re not, but we’re making this for people who are fairly advanced.”

So while we don’t get a full breakdown of the laws of time travel, we do learn that Rya is traveling on a one-way trip to the past, with no mulligans. “Time travel is a one-way street,” she explains, telling Locke that if their journey begins with him warning her about her death, it still always end with her death. He killed his granddaughter and that can’t be undone. It already happened, he just met her further down the line. As for the science of the time travel, that’s a bit more out there.

During the film, Lock meets a physicist who discovers Rya’s crimes are linked to an astronomical phenomenon. He explains, “What you may know simply as a supermoon or blood moon are actually events of great scientific significance. When the lunar cycle reaches exactly the right point, its gravitational forces react with electromagnetic pockets and theoretically creates a kind of bridge to another place entirely.” That’s why Rya’s time travel pod only touches down every nine years, when space and time line up just right. Does the science check out? Probably not, but as far as I know, no one’s cracked time travel yet, so hey, maybe it’s the moon.

In the film’s final moments, Locke finally chooses his family and his future. Rya leaves him on the beach, heading off to complete her mission (or start it, depending on your perspective,) and he accepts his daughters offer to be there for the birth of his granddaughter. As he peers out of a window at a sun-soaked Philidelphia skyline, we again see glimpses out of the office window in 2024, watching the smoke and fire recede and the flag of the “Real America Movement” disappear.

Micke explains that they originally had both a different beginning and ending scripted until budgets and schedule forced them to rethink during production. That’s how they ended up with the mirroring intro and outro scenes.

“You’re sort of able to find that harmony of like, alright, we’re looking out this window and we’re sort of seeing the world out this window. And then at the end of the movie, we’re seeing it through Boyd, out this window, and seeing the sort of perfect thing. So it was something that happened a bit by accident, a bit for the love of the Philadelphia skyline… It sort of has this mirror that you can almost start the movie and loop it again, of like these very similar images.”

As the two images of the skyline overlap in the scene, Rya explains in voice-over that if her mission is successful, no one but Locke and those involved will ever know it happened, leaving a brighter future in its place.

“It won’t make a sound, it won’t leave a scar. There will be no great tale in your time, just an echo of what might have been,” she explains. “But this is your story and it doesn’t end here, it’s written in sacrifice. It’s written in forgiveness, and it’s time to start your next chapter… right now, both of our lives are about to begin.” As Locke holds his infant granddaughter, he’s staring out at a future for his family with the first time, instead of fighting in the past.

In the Shadow of the Moon debuted at Fantastic Fest 2019 and is now streaming on Netflix.