Christopher Nolan's "Tenet" (2020) is perhaps his most complex film yet, and that's saying something from the director who gave us Inception and Memento. The film's temporal mechanics, inverted entropy, and palindromic structure have left many viewers confused. Let's break down exactly what happens, how inversion works, and what that ending really means.
Understanding Inversion: The Core Concept
Before we can understand the plot, we need to grasp the film's central mechanic: inversion. In Tenet's world, objects and people can have their entropy reversed, causing them to move backward through time from everyone else's perspective.
Key rules:
- Inverted objects move backward through time while everything else moves forward
- You experience time normally even when inverted - you just move backward relative to the forward world
- Inverted objects appear to move in reverse to forward-moving observers
- Interactions between forward and inverted matter can be dangerous (radiation)
- You need oxygen masks when inverted because inverted air can't be breathed by forward lungs
Think of it like rewinding a video while you're still playing forward. From your perspective, everything else is going backward.
The Algorithm: What Everyone's Fighting Over
The Algorithm is a device that can invert the entire world's entropy, essentially destroying the past from the future's perspective. It was created by a future scientist who had second thoughts and split it into nine pieces, hiding them in the past.
Sator (Kenneth Branagh), a Russian oligarch, is working with the future to reassemble the Algorithm. Why would the future want to destroy the past? Climate change and resource depletion have made the future uninhabitable. Their logic: if they invert the world, they can "undo" the damage, even though it means erasing everyone currently alive.
The Protagonist (John David Washington) works for Tenet, a secret organization dedicated to preventing this temporal apocalypse.
The Temporal Pincer Movement
The film's climactic battle uses a "temporal pincer movement" - a military strategy where forces attack from both directions in time. Half the team moves forward through the battle, while the other half inverts and moves backward through the same battle.
This means:
- Red team moves forward in time (normal)
- Blue team inverts, experiences the battle, then inverts again and moves backward through it
- From the red team's perspective, blue team knows what's about to happen (because they already experienced it)
- From blue team's perspective, they're moving backward through events they already lived forward
It's confusing, but the tactical advantage is clear: one team has perfect intelligence about what's about to happen because they already experienced it in reverse.
The Ending: What Actually Happens
In the final battle at Stalsk-12, three things happen simultaneously:
- The Surface Battle: Red and blue teams fight Sator's forces using the temporal pincer
- The Hypocenter: Ives (Aaron Taylor-Johnson) and the Protagonist secure the Algorithm underground
- The Yacht: Neil (Robert Pattinson) and Kat (Elizabeth Debicki) deal with Sator
Sator's plan is to activate the Algorithm at the moment of his death (he's dying of cancer). He'll kill himself on his yacht in Vietnam while the Algorithm is buried at Stalsk-12, creating a dead man's switch.
Kat kills Sator just before he can activate the Algorithm. Meanwhile, the Protagonist and Ives secure the Algorithm pieces. They succeed, saving the world.
The Neil Revelation
The film's emotional gut-punch comes when Neil reveals he's known the Protagonist for years - from Neil's perspective. The Protagonist recruited him in the future, and Neil has been moving backward through time to help.
The evidence:
- Neil knows things he shouldn't (he's already lived these events)
- His orange backpack tag matches the one on the dead soldier who saved the Protagonist earlier
- He says "What's happened, happened" and "This is the end of a beautiful friendship" for him
The implication: Neil is the soldier with the orange tag who took a bullet for the Protagonist. He inverts, unlocks the gate, gets shot, and dies - all so the Protagonist can secure the Algorithm.
But here's the kicker: Neil then inverts again (before getting shot) and continues backward through time to earlier in the film. From his perspective, he's moving backward through a friendship that, for the Protagonist, hasn't even started yet.
Some fans theorize Neil is actually Kat's son Max, all grown up and recruited by the future Protagonist. The evidence is thin but intriguing: Neil could be short for "Maximilien" reversed (Neil ≈ Max backward-ish), and Neil's age could work if he's from years in the future.
The Protagonist's Revelation
The final twist: The Protagonist learns he's the one who created Tenet. Not in the future - he'll create it going forward from this point. He's been working for his future self the entire time.
Priya (Dimple Kapadia) tries to have Kat killed to tie up loose ends, but the Protagonist kills Priya first. He's now in charge of Tenet and will spend the coming years recruiting agents (including Neil) and setting up the organization that saved the world.
It's a bootstrap paradox: Tenet exists because the Protagonist created it, and the Protagonist created it because Tenet recruited him. There's no beginning to the loop.
The Timeline, Explained
Here's the chronological order of events (not the order we see them):
- Far Future: Scientist creates Algorithm, regrets it, splits it into nine pieces, hides them in the past
- Future: Climate catastrophe makes future uninhabitable; they contact Sator to retrieve Algorithm
- Sator's Life: He finds one Algorithm piece in Stalsk-12 ruins, becomes rich, spends life collecting others
- The Protagonist's Future: He creates Tenet, recruits Neil and others
- Neil's Journey: He inverts and moves backward through time to help past-Protagonist
- The Film's Events: Everything we see happens
- Post-Film: Protagonist builds Tenet, recruits Neil, sends him back
It's a closed time loop. Everything that happens has always happened and will always happen.
The Palindrome Structure
Appropriately for a film about moving backward and forward through time, "Tenet" is a palindrome. The film's structure mirrors this:
- The opening (opera house) and ending (Stalsk-12) are both large-scale battles
- The middle features the Oslo Freeport scene, which is literally shown forward then backward
- Character names and locations are palindromes or near-palindromes: Sator, Arepo, Tenet, Rotas, Opera
- These words form the Sator Square, an ancient Latin palindrome
Nolan structured the entire film as a temporal palindrome, with events mirroring each other forward and backward.
Common Confusions, Clarified
Q: If you invert, do you get younger? A: No. You experience time normally; you just move backward relative to everyone else. You still age forward from your perspective.
Q: How can inverted and forward people interact? A: They can, but it's dangerous (radiation). Inverted bullets moving backward can "un-shoot" forward people.
Q: Who built the turnstiles? A: Tenet built them, using technology reverse-engineered from future devices.
Q: Why doesn't the future just send back an army? A: The grandfather paradox. They need people in the past (like Sator) to do their work, or they risk erasing themselves.
Q: What happens to the Algorithm pieces? A: The Protagonist, Ives, and Neil each take three pieces and agree to never see each other again, ensuring the Algorithm can never be reassembled.
The Themes
Beneath the temporal mechanics, Tenet explores:
- Free will vs. determinism: If the future has already happened, do we have choice?
- Sacrifice: Neil chooses to die for the mission, knowing his fate
- Faith: "Don't try to understand it, feel it" - sometimes you have to act without complete knowledge
- Posterity: Fighting for a future you'll never see
The Protagonist's journey is about accepting responsibility for the future, even when that future has already happened.
The Verdict
Tenet is intentionally complex, designed to reward multiple viewings. Unlike Inception, where the rules are clearly explained, Tenet throws you into the deep end and expects you to keep up.
The ending is actually straightforward once you understand inversion: the good guys win, the Algorithm is secured, and the Protagonist begins his journey to create Tenet. The complexity comes from the temporal mechanics and the non-linear storytelling.
Neil's sacrifice is the emotional core. He knows he's going to die but does it anyway because "what's happened, happened." It's a meditation on fate, friendship, and the things we do for people who don't even know us yet.
As for whether it all makes logical sense - Nolan himself has admitted the science is more conceptual than rigorous. The point isn't whether temporal inversion is physically possible, but what it allows Nolan to explore about time, choice, and consequence.
In the end, Tenet asks: If you knew the future, would you still fight for it? The Protagonist's answer is yes. And that's what makes him the protagonist.
Enjoy Christopher Nolan's work? Check out our analyses of Inception's ambiguous ending and the best plot twists in cinema, including several Nolan films.