All Your Tenet Questions, Answered

We finally understand Christopher Nolan’s new movie, mostly.

John David Washington in Tenet with questions marks over the image.
Photo illustration by Slate. Photo by Warner Bros. Pictures.

This article contains spoilers, we think.

So wait. You’ve seen Tenet? Like, in a movie theater?

I have. Twice.

Is … that a good idea?

That’s a complicated question, but the simple answer is “No.” Medical experts tend to agree that sitting in a room for hours with people who are allowed to take off their masks as long as they’re in the vicinity of a bucket of popcorn is a high-risk activity, and though theater chains have stepped up their COVID safety protocols, they’ve been evasive when pressed on the details. That said, not everyone lives in a country that has screwed up its coronavirus response as badly as the U.S. has. And there are (some) drive-ins. I wouldn’t advise you to go see it in a theater, but I can’t order you not to.

That’s not very comforting!

It’s not meant to be.

Can you tell me what Tenet’s about, at least?

Sort of? Let’s start with broad strokes. The movie’s protagonist—identified only as the Protagonist (I know)—is a CIA operative, played by John David Washington, recruited by a highly secretive organization called Tenet, whose purpose is to prevent the end of the world. It’s explained to him that the present is under attack by the future; we’re about to lose a war that, from our perspective, hasn’t even started yet. You see, in the future, an unseen enemy has figured out how to make time run backward, albeit in an extremely localized fashion. Using something called “inverse radiation,” they can reverse the entropy of both objects and people so that they move through time in the opposite direction—at least from our fourth-dimensional point of view. If those objects are stationary, they’re indistinguishable from any other; a forward-moving bullet looks the same as a backward-moving one, as long as they’re not moving. But where a forward-moving bullet is fired and then strikes its target, a backward one moves from the target to the gun. In other words, the Protagonist is told, he’s not shooting the bullet. He’s catching it. (Since it moves at the same speed either way, being in the path of the latter is just as bad, with the added side effect that the inverse radiation also infects the bullet wound.)

Inverse radiation allows objects to move backward for a potentially infinite amount of time, which means that the future enemies—let’s just call them the Future—can hide weapons, money, and technology in their time and have them retrieved in ours, which is how they engage Russian arms dealer Andrei Sator (Kenneth Branagh) as their present-tense emissary. It also allows Andrei and his henchmen, and eventually the Protagonist and his allies, to reverse their own entropy and move backward through time, although because regular air can’t pass through inverted lungs, they can only do it for the length of a tank of oxygen.

Acting on orders from the Future, Andrei has spent decades gathering the nine parts of “the Algorithm,” which is actually an irregular metal cylinder that encodes the secrets of reversing time—not just for individual objects or people but for the entire planet. Because a forward-moving entity that comes into contact with its backward-moving equivalent is instantly annihilated, activating the Algorithm would mean the instantaneous end of the world. Which would be bad.

Why would anyone want to do that?

That’s not entirely clear. (After two viewings and hours poring over Reddit dissections, the best I can hazard on some of these questions is a well-informed guess.) Christopher Nolan, enemy of intelligible dialogue that he is, buries the explanation in a crackly walkie-talkie transmission near the end of the movie, but Andrei suggests that the Future is at war with the past “because the oceans rose and the rivers ran dry,” i.e., because of catastrophic climate change. With no path ahead of them, their only hope is to change direction and carve out a future in our past. They presumably don’t think that means instant annihilation, or at least they’re willing to risk it, since with every other natural resource exhausted, the only one left is time. But it’s also, as Tenet admits, an extension of the shortsighted thinking that caused the climate crisis in the first place. As the Protagonist’s ally Neil (Robert Pattinson) explains, “Every generation looks out for its own survival.”

But wouldn’t blowing up their own past mean the Future is effectively committing suicide?

You are thinking of the grandfather paradox, the famous thought experiment in which a time traveler murders his own grandfather, thus ensuring he will never be born, and thus never able to travel back in time to commit the crime in the first place. As Neil explains to the Protagonist, the nature of a paradox is that it has no solution, but the Future is at least betting that they can “push grandpa down the stairs, gouge his eyes out,” and still survive. For his part, Neil simply believes that “What’s happened, happened,” meaning that while you can introduce new variables into the time-travel equation, you can’t change something that’s already occurred. That might mean that the very existence of the Protagonist’s team in the present means they’ve already accomplished their mission in the future—but, first, they’re not taking any chances, and, second, that would be a very boring movie.

Let’s back up a sec. (Thematically appropriate, no?)  “Inverse radiation.” Is that, like, a thing?

It is not.

What about reverse entropy?

Probably not? Stephen Hawking once theorized that as the expansion of the universe slowed and eventually reversed, time itself might appear to run backward, but he admitted his theory was in error, and according to the 2011 winners of the Nobel Prize in physics, the expansion of the universe is actually accelerating. Nolan might have had the backing of theoretical physicists on Interstellar, but he’s on his own here.

So it’s all kind of nonsense?

There’s a reason the scientist who explains everything to the Protagonist tells him that he shouldn’t try to understand it—just “feel it.”

Hmm. OK. Let’s get back to the plot, I guess. So in the Kyiv opera siege that opens the movie, what are the Protagonist and his crew trying to protect?

It’s a piece of the algorithm—although everyone, including the Protagonist, seems to think it’s weapons-grade plutonium-241, which is sometimes how they refer to it. It’s the possession of an undercover CIA asset who’s using the opera’s coat check as a dead drop, but the handoff is interrupted by a group of rogue “free Russians” who want it for themselves. As he’s trying to stop those rogue agents from blowing up the opera house to cover their tracks, the Protagonist spots evidence of an inverted bullet, one that’s presumably about to pass through him. But he’s saved by a mysterious figure with a red string attached to his backpack—one whose identity we won’t learn until the very end of the movie.


Yeah, the more you explain this, the more complicated it gets.

So what is “Tenet,” exactly?

You picked a good time to ask. After the Kyiv siege, the Protagonist is captured and tortured, but he bites down on a CIA-issued suicide pill rather than talk. (It’s one of several times in the movie his character ought to have died, which has already given rise to numerous fan theories.) The suicide pill turns out to be a fake, but it proves he’s loyal to the point of death, which is useful when your enemy is time itself. At first all he knows about Tenet is the word itself, and a gesture involving the interlaced fingers of two hands, which seems to represent the collision between the two directions of time. But the metal alloy used in the inverted bullet from the opera siege leads him to an Indian arms dealer (Dimple Kapadia), who tells him about Andrei and the coming war.

It’s also a palindrome, right?

It is! Very good. The word tenet reads the same backward and forward, one of several references to reversibility embedded in the film. Andrei Sator’s surname comes from the Sator Square, a five-by-five grid of interlocking letters that reads the same in every direction. It was first discovered in the ruins of Pompeii, which is a location that Andrei’s wife, Katherine (Elizabeth Debicki), and their son seem especially keen on visiting.

The other five words in the Sator Square all turn up in the movie at some point: There’s Rotas, the name of the security company that guards Andrei’s warehouse in the Oslo airport; Opera, the location of the movie’s first set piece; Arepo, the name of the art forger whose bogus Goya Katherine, who works at a high-priced auction house, arranged to have sold to her husband, and which he’s now using as leverage to keep her from leaving him. And there’s the central word in the Sator Square, the axis on which it turns: tenet.

Tenet is also the word ten backward and forward, which becomes key to the movie’s climactic sequence, in which synchronized attack teams move through time in opposite directions on a 10-minute countdown, performing what the movie calls a “temporal pincer.”

A temporal pincer? What is that?

In classic military tactics, a pincer movement is when you attack the enemy from both sides at the same time. In a temporal pincer, you attack from both directions in time. One attack team proceeds through the event, taking careful notes, and then briefs the second team after it’s over. The second team then reverses direction and proceeds backward from the end, armed with the knowledge of what’s already happened. There are two of these in Tenet: the attempted heist of the final piece of the Algorithm before it’s transferred to Andrei and the movie’s climactic battle, which I’ll get to in good time.

I sort of get it. (And I see what you did there.) But can you walk me through one of these temporal pincer deals?

Sure! There are two things to keep your eyes on when you’re trying to get a temporal pincer movement straight. One is the red-and-blue coding used in the movie’s final battle, where the good guys split into two units: a red team, moving forward through time, and a blue team, moving backward toward them. That pattern is actually introduced earlier, during the Protagonist’s attempt to secure the last piece of the Algorithm, although there’s no way to know that’s what you’re looking at the first time through. The Protagonist’s team steals the piece—which the Protagonist, not yet trusting Neil, tells him is plutonium-241—from a convoy by trapping the armored car in which it’s traveling between two moving trucks: a red fire truck on the left and a blue tractor-trailer on the right. And at the end of the chase, he’s taken to Andrei’s warehouse, which has been split in half by a transparent barrier with a “temporal stile”—basically a revolving airlock that allows you to change the direction in which you move through time—at one end. On the red side, time moves forward. On the blue side, it’s moving backward.

The second thing to watch for is simpler: oxygen masks. Because inverted people can’t breathe regular air, anyone you see wearing a mask over their mouth is probably inverted, even if you can’t see which direction they’re moving.

So how does this temporal pincer heist work?

If you watch the beginning of the sequence carefully, you’ll see Andrei lingering near the red-tinted entrance to the temporal stile, staying behind and instructing his men to tell him everything that happens. That’s because he’s planning a temporal pincer: If the handoff doesn’t go smoothly the first time through, he’ll know exactly what happened, and he’ll be able to stop it as he moves backward through time. The tricky part is that the movie implies that this has already happened before the first time we see the Protagonist and Neil successfully grab the 241. (This will make more sense in a moment.) That’s why we see an inverted, gas mask–wearing Andrei holding Katherine hostage after they’ve pulled off the heist (and why you can also see him sitting behind the wheel of a car as the Protagonist is marched into the warehouse). The Protagonist tricks Andrei by removing the 241 from its case and exchanging an empty case for Katherine’s life. And he hides it by—hold onto your butts—handing it off to a backward-moving version of himself, who has caught up with the forward-moving Protag. (The movie cuts away after they lock eyes the first time through, but you can see the handoff the second/reversed time.)

But once Andrei realizes the 241 is in the car the reversed Protagonist stole, he performs a second temporal pincer, knowing that as soon the reversed Protagonist places it in his car, it will be waiting for Andrei in the future. All Andrei had to do was figure out where the Protagonist put it, and then find the right point in time to grab it from him.

Um, what?!?!

Yeah, I’m sorry. This is a movie that becomes less clear the more you explain it.

So it’s possible not only to change the past but to do it more than once?

Yup. Think of the past as a Google doc that anyone with a temporal stile can edit. Tenet effectively allows us to look at it with Track Changes turned on.

How many times can the same person move through the same timespan?

Effectively an infinite number, I think? One character in Tenet does it at least three times … but we’ll get to that.

OK, now my brain hurts. Let’s skip to the climax before I have a stroke.

So here’s the basics. Andrei has assembled the complete Algorithm, and he’s preparing to bury it in an underground former nuclear test facility in his Siberian hometown, a Soviet “closed city” called Stalask-12. Once it’s buried there and he transmits its location to the Future, it’s all over. The trick is that if Andrei knows he’s failed, he’ll just make a temporal U-turn and try again, so the Protagonist and his team have to retrieve the Algorithm without Andrei knowing it. Oh, and by the way, this is all taking place in the past—on the same day as the Kyiv opera house siege that opened the movie.

How do they know Andrei’s plan?

Two reasons. One, there’s evidence of an explosion in Stalask-12 on that day, which is Andrei’s way of sealing the Algorithm in an underground cavern until the Future can dig it up. Two, Katherine tells them that he’s got terminal cancer and has been planning to end his own life. On the day of the siege, she and Andrei were moored off the coast of Vietnam, and she made one last attempt to reconcile with him. She reasons that he’d choose that brief window of happiness as the moment to end it all, both for himself and the entire world.

So how do they plan to stop Andrei from giving the Algorithm to the Future?

Another temporal pincer. The Protagonist’s team, which now includes a small battalion of soldiers, will split in two and attack the Stalask-12 burial site from both ends of a 10-minute window. But their goal isn’t to save the Algorithm: It’s to fail, or at least appear to. The entire operation is a giant diversion, one that includes blowing up a building with both forward and reversed bombs at the five-minute mark. The only objective that actually matters is the one to be carried out by the “splinter group” composed of just two people: the Protagonist and the leader of the time-traveling Resistance, Ives (Aaron Taylor-Johnson). Their job is to sneak through an underground tunnel and retrieve the Algorithm without anyone knowing, because the only way to ensure that no one else can travel through time and undo their plan is if no one knows it’s missing.

Katherine’s job is to keep Andrei happy and unsuicidal, because the instant his heart stops, his fitness tracker will trigger an email blast with the location of the Algorithm. That part … doesn’t go so smoothly.

Does that plan actually work?

It does, although not without a few hitches. The Protagonist and Ives reach the cavern where the Algorithm is going to be buried, but they’re stuck behind a locked gate, watching helplessly as Andrei’s henchman prepares the Algorithm to be lowered into its time capsule. But then they notice a dead body on the other side of the gate, with a familiar red string hanging from its backpack. Moving in inverted time, that body springs back to life and unlocks the gate, allowing the Protagonist to move through it as Red String Guy sprints backward up the entrance tunnel. Henchman killed, Algorithm saved, but the Protagonist and Ives are still stuck deep underground, seconds before the bomb goes off—and meanwhile Katherine, unable to suppress her loathing of her abusive husband, shoots him dead, which means there’s no backup plan. Fortunately, Neil, who started the operation as part of the backward-moving blue team, has found a temporal stile on site and reversed his own direction. (That’s him you hear honking his horn just before the Protagonist triggers the booby trap that seals the entrance tunnel to the cavern.) Knowing that they’re about to be trapped underground when the explosion is triggered, Neil lowers a rope to the Protagonist and Ives, and pulls them out just in the nick of time. Hooray!

So who is the guy with the red string?

The guy with the red string is also Neil. He actually moves through the final battle three times. First, he attacks as part of the backward-moving blue team. Then he reverses himself and, moving forward, pulls the Protagonist to safety. And then, at some unspecified point in the future, he turns around and goes through the battle backward again, unlocking the gate and being shot dead by Andrei’s henchman. As if that weren’t enough, he also, at some other point, travels far enough backward in time that he can make it to Kyiv and save the Protagonist’s life in the opening scene—which, lest we forget, is taking place at exactly the same moment. So there are at least three iterations of Neil scattered throughout time, and potentially a lot more.

I think I’m going to go lie down for a bit. But before I do, one question: I’ve seen people on the internet throwing around the theory that Neil might actually be Katherine’s son. Is there any truth to that?

I mean, maybe? To quote Neil himself, “it’s unknowable.” But it would explain some things. We know from Neil’s speech that he’s been part of Tenet for a long time and that he was recruited by the Protagonist at some point in the future (which is Neil’s past). Given that Pattinson is in his 30s and Katherine’s son looks to be about 10, the math would work: The Protagonist recruits him 10 years from now, and Neil spends the next 10 years traveling back to the point at which it all started. It’s a temporal pincer, carried out over a decade instead of 10 minutes.

Neil doesn’t seem to show any particular attachment to Katherine, so that part is kind of a wash. But it would explain why Katherine seems to know more about how that last day will play out than anyone has told her. At the beginning of the movie, she tells the Protagonist that when she returned to Andrei’s yacht on the day of the opera siege and the Stalask-12 battle, she saw a woman dive into the water from the top deck, and Andrei was nowhere to be found. The ending establishes that the diving woman was Katherine herself, and Andrei was missing because she’d killed him and thrown his body into the ocean. When Katherine returns to the yacht in the final sequence, it’s with the explicit aim of not killing Andrei, but the first thing she does is unclip the safety wires around the edge of the boat, and she “accidentally” squirts sunscreen all over the deck, which eventually makes it easier to slide his dead body over the side. Neil reiterates several times that the team’s best defense is ignorance: the fewer people who know the details of the operation, the less vulnerable they are to being found out. So it would make sense if Neil told her what she really needed to do and left the Protagonist, and the audience, out of the loop, especially if he had an added reason to trust her.

So wait. You’ve seen Tenet? Like, in a movie theater?

Well done.

For more Slate coverage of Tenet, listen to a spoiler-filled conversation about the movie between Slate’s Sam Adams and Vox’s Alissa Wilkinson.