Tenet on HBO Max: That ending explained and all your questions answered

Christopher Nolan's time-twisting movie is streaming now. Here are some answers to what the hell happened.

Jennifer Bisset
Jennifer Bisset
Jennifer Bisset Former Senior Editor / Culture
Jennifer Bisset was a senior editor for CNET. She covered film and TV news and reviews. The movie that inspired her to want a career in film is Lost in Translation. She won Best New Journalist in 2019 at the Australian IT Journalism Awards.
Expertise Film and TV Credentials
  • Best New Journalist 2019 Australian IT Journalism Awards
Jennifer Bisset
5 min read

Tenet is out now in the US and UK. Don't forget your mask.

Warner Bros.

Tenet is streaming now on HBO Max, as well as on Amazon, Apple TV and Google Play. Unlike in theaters, you can now turn on subtitles and rewind the confusing bits to figure what the heck's going on.

Christopher Nolan's sci-fi spy caper has been criticized for its confusing plot and even its sound mixing rendering dialogue inaudible. And yet the eye-popping action sequences, stylish James Bond wardrobe and nerve-shredding soundtrack still manage to swallow you in an intoxicating wave of blockbuster spectacle.

But what about that time-bending plot? Here are some answers to what the hell happened.

Read more: The Haunting of Bly Manor ending explained, and all your questions answered

Warning: Spoilers ahead


John David Washington.

Warner Bros.

What's inversion?

In the future, a technology has been developed that reverses the entropy of people and objects to move backward through time. Entropy is a complicated physics concept which explains why some processes occur spontaneously while their time reversals do not. "Ice melting, salt or sugar dissolving, making popcorn and boiling water for tea are processes with increasing entropy in your kitchen," according to one explanation. In Tenet's universe, the Protagonist (John David Washington) is shown a bullet with inverted entropy that returns to its gun. You can tell if a human has been inverted, because they have to breathe special oxygen through a mask -- regular air doesn't go through inverted lungs. If you contact your "forward" self, it causes "self-annihilation," meaning you kill yourself. Complicated stuff.

What's the Algorithm?

Nine objects, hidden in nuclear faculties, form an algorithm that reverses the entropy of the Earth. Setting off the Algorithm ends the world.

What's Sator's plan?

Russian oligarch Andrei Sator (Kenneth Branagh) is in contact with an unknown agency in the future. Sator plans to set off a doomsday device, also known as the Algorithm, that will reverse the entropy of the entire planet. He's dying from inoperable pancreatic cancer and believes if he can't live, no one can. Sator travels back to the holiday with Kat (Elizabeth Debicki) in Vietnam when they were both happiest, planning to die there peacefully and set off the doomsday device with a dead man's switch linked to his heartbeat.

Why's the future working with Sator?

In the future, everything is destroyed. An unknown agency is working with Sator to kill everyone in the past, because they're responsible. The people in the future believe that reversing the entropy of the Earth will prevent climate change. With no other choice for their survival, they're willing to destroy their ancestors and threaten their own existence -- the grandfather paradox.

Why Sator?

Sator grew up in the Soviet Union in a small community acting as a "closed" or "secret" city with sensitive facilities, such as nuclear research sites with a plutonium production plant. Sator was in the right place at the right time as a teenager, when he dug up a piece of the Algorithm in the rubble of his home in Siberia. The scientist in the future who created the Algorithm has been hiding the pieces back in time, realizing no one should have the technology. The unknown agency charges Sator with recovering the pieces and dropping the finished Algorithm into the "dead drop" in his nuked home town, where they'll find it centuries from now. The agency buries time-reversed gold bars that Sator digs up for payment.

Who saved the Protagonist at the opera house?

While foiling the terrorist siege at the Kiev opera house, the CIA secures an unidentified object (which later turns out to be a piece of the Algorithm). After retrieving the object, the Protagonist, a CIA agent, is saved by a masked gunman. We see the gunman wearing a red string on his back -- the same red string Neil (Robert Pattinson) wears on his backpack at the end of the movie. So it was Neil who saved the Protagonist in the opening gunfight.

How does the 'temporal pincer movement' work?

Let's look at this through the scene where the Protagonist steals the "plutonium" from an armored car for Sator. Half of Sator's men enter through a portal called a "turnstile," allowing them to move backward through time, while the other half move forward. Sator makes off with the piece of the Algorithm with the benefit of knowledge shared between the two teams. That's the "temporal pincer movement."

How did Kat survive after being shot?

Sator shoots Kat with an inverted bullet, which means radiation poisoning as well as regular bullet damage. To head that off, the Protagonist and Neil take her through the temporal turnstile so she's also moving backward in time, just like the bullet. They then take her to the Oslo "freeport" art storage facility and go through another turnstile to move forward in time again.

Why is Kat under Sator's control?

In a nutshell, Kat knowingly sold Sator a forged painting. To gain her trust, the Protagonist and Neil try to steal the painting from the "freeport" in Oslo Airport.


The destroyed building.

Warner Bros.

How did they set off 2 explosions in that building?

In the closed city where the Algorithm is stored, two teams participate in the operation to stop the doomsday device's detonation. The red team is moving forward in time, while the blue team is time-reversed. They're using the "temporal pincer movement" over a 10-minute period, with the blue team kept separate from the red up in helicopters. By setting a timer, the red team (those moving forward in time), detonates a bomb in the bottom half of the building at the 5-minute mark, while the blue team does the same in the top of the building by counting backward from 10 minutes to the same moment.

What happened at the end with Neil?

In the Algorithm room, the Protagonist and Ives (Aaron Taylor-Johnson) encounter a locked gate. On the other side, they see the corpse of a masked soldier, who wears a red string on his backpack. One of Sator's men tries to shoot the Protagonist, but the masked man springs back to life, takes the bullet and unlocks the gate, allowing the Protagonist to prevent doomsday. He then reverses out of the tunnel. We later see the red string on Neil's backpack, when he reveals that he was recruited by the Protagonist in the future. So the masked soldier who dies is Neil.

Who's Neil?

Here's a fun fan theory: the identity of Neil may have an extra layer. He has some similarities to Kat -- including Pattinson's dyed blonde hair and posh English accent -- and he shows a level of tenderness while nursing her that suggests a deeper connection. Which has led some viewers to speculate that Neil is in fact Kat's son. We see Kat's little boy Max during the film, who may have grown up into Pattinson and then been inverted to come back and help the Protagonist defeat his vicious father. Hey, it's a theory. 

Who's the Protagonist?

The Protagonist travels to London to save Kat from arms dealer Priya (Dimple Kapadia), who believes she must tie up loose ends. The Protagonist shoots Priya, realizing he will go back in time and found the secret organization Tenet.

New Movies Coming in 2023 From Marvel, Netflix, DC and More

See all photos