BIG spoilers though I can’t guarantee they’re all accurate. It’s worth bearing in mind that the only reason I didn’t fail my Physics O’level is because I didn’t take Physics O’level. Not in this reality, anyway. (My 4-star review is here)
Well that was loopy, right?
Okay, let’s start with a theory rather than a spoiler. This is NOT mentioned in the film but I think Neil is… Kat’s little boy Max, all grown up.
Now let’s dive in, I mean out (some of this is also in my review but who doesn’t love a straightforward timeline? Oh).
Neil is from the future and the whole story is a temporal pincer movement. Neil was recruited by the (future) Protagonist in the future and is working backwards. His and the Protagonist’s knowledge are informing their joint actions. (Remember how Neil knows what the Protagonist drinks at their first meeting.)
The film takes us from the rubble of the Soviet Union, its collapse the most dangerous time for nuclear material, to the future, though we never see what is happening there. Instead we see the ripples coming back. Cold War sci-fi, we could call this.
TENET starts with a raid on an opera house; later the Protagonist is tortured by the Russians, but he takes a suicide pill. It’s fake, as his bosses just want to know if he would betray his team. He passes the test and is introduced to TENET, the name; plus a gesture of linked fingers, which looking back encapsulates the moving forward and backwards of the temporal pincer movement.
He’s then taught about reversed entropy by Barbara the scientist. TENET is about time inversion not time travel, so objects move backwards in time when their entropy is reversed; you need a temporal stile to move from normal time to inverted time. As we find out later, your lungs can’t cope so you have to wear a breathing mask (which is really helpful to the viewer when two versions of one person are around at the same time). The wind is at your back, fire is ice, gravity feels normal but “you are inverted, the rest of the world is not”. If someone meets themselves it’s game over: annihilation.
The bullets Barbara shows him are traced back to Priya, an Indian arms dealer who uses her husband as a front. No one suspects a woman. He links up with Neil and both men bungee in reverse up to her luxurious apartment (very clever!). She directs him to Russian billionaire Andrei Sator, who has access to the temporal stiles which they can use to reverse entropy objects and people.
To get to Sator he has to go through Sator’s wife Kat, an art dealer who double crossed her own husband by authenticating a fake Goya that he bought. But first he has a very brief lunch with London intelligence bigwig Sir Michael Crosby (Michael Caine) who has a good dig at Brooks Brothers (apparently that suit won’t cut it with billionaires). His meeting with Kat ends up with her explaining she is trapped in her miserable marriage because of the drawing; she then talks about a woman she saw diving off their boat on their Vietnamese holiday. Kat envies her not because she might be having an affair with Sator but because of her freedom.
Sator’s men beat him up but he fights back and destroys them. The Protagonist decides to steal the Goya from the Oslo Airport free port where it is stored so Sator has no hold over Kat any more. He and Neil crash a plane into the free port, but they fail to get the drawing as Sator has removed it. While escaping, the Protagonist fights with a black-clad man who is fighting in reverse.
Introduced to Sator, he agrees to obtain some plutonium so show good will, though it’s actually the last piece of the Algorithm weapon. This is the temporal pincer movement car chase, which he takes part in twice (at the same time). But instead of handing over the goods he hides it in the glove box. Afterwards Sator, moving between timelines, shoots Kat, and she, the Protagonist and Neil go into the past with one of those time stiles (to the Oslo attack) to save her. (I will freely admit I still don’t understand why reversing the entropy can save her.) This time the Protagonist comes across himself from the free port break in, and they fight; yes he is also the black-clad reverse fighter that he fought during the Oslo attack.
Sator is dying of pancreatic cancer, presumably caused by the radiation he was exposed to as a young man. Living in one of the Soviet Union’s secret cities as the Union fractured, when a warhead partially exploded and destroyed the city he alone was prepared to take the money offered by those from the future and search for part of the mega-weapon in the radioactive rubble.
That money set him on his way and gave him a way out of the dying system, just as people in the future were looking for a way our of their dying planet.
By the time we meet him he has control of these time stiles, through which he can invert objects and people. He has also tracked down eight of nine hidden sections of the Algorithm, the super-weapon from the future. Setting it off will destroy the Earth and everything on it up until that point in time. He obtains the final section from the Protagonist after the big car chase, which takes place in real time and inverted time. Sator has set up a pincer movement for this too, so he knows how it’s going to play out.
Sator is now planning to go back and kill himself at the time he was most happy, the last family holiday to Vietnam on the boat, and with his death he’s going to take out the whole world up to that point too – using the dead man’s switch, disguised as the fitness tracker he always wears.
Kat guesses he’ll go back to that holiday, and Neil, Kat and the Protagonist use one of the time stiles to go back to that time. Neil and the Protagonist will rescue the weapon, while Kat will stop Sator killing himself too soon. (Kat goes back a day further in time than Neil or the Protagonist, to give her time to get to the boat. She’s not wearing a breathing mask as she is now moving forwards through time.)
In terms of why Sator is doing this – why he wants to destroy everything when he dies, particularly considering his love for his young son Max – Kat claims it’s for the same reason he won’t let her go. If he can’t have something, in this case life, then nor should anyone else. He also speaks about how much he regrets bringing a child into a dying world, that it is his greatest sin.
But he’s also working with people in the future, where the planet is so damaged that destroying us is their only chance (I think! I’m not sure whether they want to retreat through time to save themselves or create a separate reality, a parallel universe, when the past is destroyed).
Destroying the past, though, gives rise to the Grandfather Paradox, as Neil explains: if you go back in time and kill your grandfather before they meet your grandmother, will you even exist? (I think this is solved by your changes to time splitting off into a parallel reality but don’t quote me.)
Actually though, I like the idea of Sator destroying literally everything out of sheer petulance rather than as part of a deal. It fits with that over the top, ’60s megalomaniac villain sensibility that weaves through TENET, sometimes rearing up without seeming at all incongruous among the action set pieces, convoluted physics lessons and personal dramas.
Usually a protagonist has to kill the villain; here they have to keep him alive. For now anyway. Another “temporal pincer movement” sees two groups of soldiers set out to retrieve the now-completed weapon Sator has hidden underneath the dead city, ready to go off as soon as he dies. One group are going forward in time, the other in reverse, wearing their breathing masks, each side learning from what the other has been through.
They’re really a decoy, while Ives and the Protagonist head into the bunker. Once there, they find a locked mesh door and one of Sator’s henchmen with the Algorithm weapon. On the other side of the door is a dead body. Sator, on the phone, tells his henchman to shoot the Protagonist but the body is inverted and rises up, opening the door then leaves, backwards. The Protagonist and Ives manage to retrieve the weapon, just in time.
Meanwhile on their boat, Kat is meant to be distracting her husband so he doesn’t kill himself until his weapon has been retrieved. She gets fed up and shoots him anyway, after she’s told him to his face before he dies that he’s lost; for Kat this is key despite the risks of killing him too early. (Later she tells The Protagonist that she knew he’d think of something but I have to admire her gutsy, potentially world-ending obsession.)
She dives off the boat (yes she’s the woman she saw diving off earlier in the film), and Sator’s humiliation is complete when his dead body is dragged along behind their escape speedboat – just as original Kat returns in a boat from a day out on the mainland with Max.
But back to that final backwards/forwards battle for the Algorithm. Once they have retrieved it, Ives, Neil and the Protagonist each stand in the sand with a third of the weapon. Humans are always the weak link. Ives says they should kill themselves as no one who knows about what has happened should be allowed to live, but he lets everyone go, saying if he sees them again he will kill them.
Neil’s goodbye is more poignant. The corpse in the bunker was him (watch for the red string on his rucksack there, and on the man who saves the Protagonist in the movie’s first scenes at the opera house), and now he has to go back to the past and sacrifice himself.
Before he goes, Neil explains that the Protagonist actually recruited him in the future. For the Protagonist this is their first mission together, but for Neil it’s their last. (Another Neil, from Get Your Comic On, suggested to me that TENET Neil is the movie’s River Song, which should please Doctor Who fans.)
Then we cut to London, and outside Max’s school. Priya, the arms dealer, is there in a car with a guard, about to shoot Kat, because of what she knows. It’s the tying up of loose ends. But Kat has noticed the car and called the Protagonist on a device he gave her previously, a device he told her to use if she’s ever in danger. The Protagonist kills Priya; then Max and Kat walk off hand in hand.
Finally talk about hiding in plain sight. TENET is TEN / TEN, the last word reversed, and refers to the climactic battle when ten minutes is key. (I won’t lie, I had to google that bit.)