# How does Sator get the algorithm after the car chase?

This question contains many spoilers for Tenet. I asked it when Tenet was in the cinemas and didn't have a DVD/streaming release, so I'd only seen it once.

I'm trying to work out exactly what happens in the car chase sequence. I think I understand where most of the characters go, but there's a couple of objects where I don't understand what happens to them.

The main one is the silver box that later turns out to be part of the algorithm. It seems that this is what happens:

Initially the protagonist has the algorithm with him in his car. Then at some point the silver car un-flips and joins the chase.

In a third car, Sator appears to be counting down on his fingers (though from Sator's point of view he's counting up), and the protagonist throws him the orange case that originally contained the algorithm. However, we later find out that he threw the empty orange case to Sator while almost simultaneously throwing the algorithm into the silver car.

Later, the protagonist goes through the turnstile, exits the building inverted, and finds the silver car.* For some reason, he doesn't seem to realise that at this point the algorithm is (as far as I know) somewhere in this car.† ‡ He then drives off and enters the car chase. The algorithm then jumps up from somewhere and flies into the BMW, which is how we know he threw it in there in forward time.

He then crashes the car, and Sator catches up with him and sets it on fire. But as the diagram above shows, the algorithm isn't in the car at this point - in the inverted time line, it's already jumped into the BMW.

After that the protagonist loses consciousness, and when he wakes up he says that Sator has the algorithm. Later we find out that this is true, since all the algorithm's components have been assembled at the final battle.

So in forward time, the algorithm seems to end up sitting in the silver car, parked outside the turnstile facility, which has been taken over by Ives' team. The question is how Sator's people get hold of it after that. It happens off screen, but is it explained or hinted at?

Sator himself can't have picked it up, because he inverts before the protagonist gets into the car. Unless he uninverted later, before inverting again and going back to Vietnam.

The other thing I don't understand is what happens to the orange case that the algorithm was in originally. The (non-inverted) protagonist throws it to Sator. But this Sator is inverted, which means that from his point of view it jumps out of his hands and into the protagonist's. (After that he starts counting upwards on his fingers for some reason.) But how did Sator get hold of it before that, from his perspective? At some point it's by the side of the road, but if it was thrown from the inverted car he wouldn't have had it at that point to pass it to the protagonist. I probably missed something here - which car was it thrown out of, and when? (On re-watching, in reverse-time we see the orange case jump off the curb into the non-inverted Mercedes, which inverted Sator is riding at that point in time. I guess we have to assume that it was thrown out of the car by its non-inverted driver.)

*In my headcanon this is an inverted getaway car that Sator's gang left outside the inverted half of their hideout. This explains why the car itself seems to be inverted, and also explains why there's a fancy fast car so conveniently placed at that location. Nope, that doesn't make sense - they would have to invert the car in the future in order for it to be there at that time, but Ives' team owns that facility now. Sator's team could re-capture it in the future and invert the car then, or invert it somewhere else, but then why would they go out of their way to put their inverted car there, knowing that it would be used by the protagonist in the car chase? Unless that's how they got hold of the algorithm, in the future, when they inverted it. But it seems more likely that it's just a normal car and it's just cinematic license that it behaves inverted when the protagonist drives it. (This point continued to bug me, so I've asked another question here.)

If he did realise that and tried to take it out of the car it probably wouldn't work, because it would make it impossible for him to have thrown it there in the first place. But I guess there's nothing to stop him telling one of his friends to go back through the turnstile and pick it up in forward time. He could then go and enter the car chase, to make sure the algorithm would be there in the first place. I suspect the idea is that he hasn't quite understood how time inversion works, so he thinks the algorithm will come into the Saab when his other self throws it.

Having watched it again on the small screen, he does check behind the driver seat when he first gets into the car, so maybe he knows the algorithm should be there after all, and is looking for it. He doesn't seem to look very hard, though, and fairly quickly gives up and drives off.

• Have you checked the other questions and answers about Tenet? Oct 26, 2020 at 17:19
• @BCdotWEB yes, I've read all of them in detail. Oct 27, 2020 at 1:43

If you take Sator's perspective, it is easier that way.

1. Sator take his wife to his warehouse and beats on her. (shown to audience)
2. Sator listens to his radio about how everything goes during the car chase scene, there are two Sator throughout the car chase scene, one inverted and one not; we are taking the non-inverted Sator's perspective. (happens off screen at the same time of the car chase, not shown to audience)
3. Sator enters the red room, beats on the captured protagonist and asks him where is the algorithm part. The protagonist lies to him "it is in the BMW" (shown to audience)
4. Sator sees through the window that the inverted Sator starts walking backwards to the turnstile; he realises it is time to invert himself. At this moment, Sator is about to become inverted and about to look for the BMW for the part. More soldiers arrive and chase Sator off into the turnstile. (shown to audience)
5. Sator becomes inverted and starts to interrogate the non-inverted protagonist across the window; but everything inverted Sator speaks is inverted now, therefore there is radio to translate inverted Sator's questions (shown to audience)
6. The inverted Sator threatens to the already injured Kate first then shoots her, the already injured Kate becomes unshoot (her wounds heals up and the bullet returns to Sator's pistol). (shown to audience)
7. Inverted Sator takes non-inverted Kate with him, out of the warehouse. (shown to audience)
8. Inverted Sator goes to the scene where shooting is happening, Sator's men are shooting against the cavalry Neil has called over. But inverted Sator does not find the part from the BMW. (how inverted Sator gets to the scene is not shown to audience, we are only shown inverted Sator is looking for the BMW car during the shooting)
9. Inverted Sator and his inverted driver get into a car, chases up the AUDI with only Kate trapped in it and they jump into the AUDI. (shown to audience but it is in inverted order, e.g. what we see is Sator and his driver escape from the AUDI into a car, leaving Kate to become trapped)
10. Inverted Sator throws the orange box to the protagonist (shown to audience but this throwing scene looks like both side are throwing/catching the orange box)
11. Inverted Sator sees the car in the middle is driven by inverted protagonist and also sees the protagonist throws the part into the car in the middle (shown to us)
12. Inverted Sator rams inverted protagonist's car. (shown to audience)
13. Inverted Sator points his gun to Kate and demands the protagonist for the orange box. (shown to audience but it is inverted)
14. Inverted Sator drives back to the inverted protagonist and sets his car on fire. (only the fire-setting part is shown to audience)
15. Inverted Sator now knows exactly where the part is. He radios his normal henchmen to take it out of the car which parks outside the warehouse. (not shown to audience)
• I guess it makes sense that Sator just tells his henchmen to get it later. (It's a bit annoying that the good guys don't do the same thing, since they're occupying the warehouse when the car is there and could easily just go outside and get the box before Sator's people can reach it, but I guess they just didn't think of it.) Oct 27, 2020 at 10:10
• What about the orange case - does Sator already have it when he gets into the speeding Audi? How does he get it? Oct 27, 2020 at 10:11
• Sator throws it away after he discovers it is empty. The inverted protagonist sees the box being un-thrown into a moving AUDI car. The inverted protagonist also puts a smartphone inside so that he could spy on the people in that AUDI car. Oct 27, 2020 at 10:43
• Is Sator inverted at the time he throws it away? If so that means he's catching it, not throwing it. He must catch it first, then realise it's empty, and then throw it to the protagonist, after that. Oct 27, 2020 at 11:27
• Yeah, inverted Sator unthrows this empty orange box, checks it out, then uncatches it to the protagonist. Oct 27, 2020 at 21:25

This is a self-answer, because after watching the film a couple more times I think I've figured it out.

The thing that I didn't notice the first few times I watched the movie is that after Sator shoots Kat and the protagonist decides to invert, all the soldiers invert with him. So in forward time, what happens is this:

1. Ives and his team converge on the facility and capture it.
2. At the same moment, Sator inverts, causing both forward and inverted Sator to disappear, which seems to leave only the Tenet team inside the facility.
3. Shortly after this, inverted copies of Kat and the Tenet team converge on the facility, including the inverted protagonist, who arrives in the Saab and leaves it outside with the algorithm inside it somewhere.
4. A little later, all of the Tenet-affiliated people enter the turnstile and invert, leaving the facility empty.

At this point the algorithm is just sitting in the Saab outside the turnstile facility, which is empty and unguarded. There's nothing to stop Sator's people from picking it up, since not all of them inverted.

This seems a tactically odd choice for Ives to make, but given that everyone did invert at that point there was no time for anyone on the Tenet side to re-invert and pick the algorithm up. I'd previously thought that the turnstile is controlled by Tenet from that point on, but it isn't - they're only in control of it for a few minutes before they leave again.

It's also somewhat odd that there was only a small unit with Ives on that mission, since they apparently had access to a much larger fighting force, along with ships and helicopters and their own turnstile facility, but I think we can put that down to the whole sequence of events being pre-determined to happen that way, together with the secretive way the Tenet organisation is structured.

Another thing I missed is that the protagonist's main reason for going back out and driving the Saab was not to capture the algorithm but to prevent Sator from shooting Kat again in the past. This explains why he gives up looking for the algorithm so quickly before driving off - it just isn't the main thing on his mind.

• A comment on my point about it being a tactically odd choice: perhaps it isn't after all. Tenet might well have a policy of "don't hang around longer than necessary near a turnstile that hasn't been permanently secured." If Sator decided to attack from the future then forward and inverted copies of the attack force could emerge from the turnstile at any time. Ives' team must have prepared to invert in Talinn anyway, since nobody seems too worried about how they'll escape when inverted or where they'll revert afterwards, so I guess he just decided to do it as soon as possible to be safe. Mar 2, 2021 at 3:26

The Protagonist's lie successfully foiled Sator's pincer movement operation. Sator did not get the last section of the algorithm from the car chase event or its immediate aftermath (= the Protagonist left the section in the Saab). Somebody else took it from the Saab. Sator got it from... well... ignorance is our ammunition. ;)

This could be confirmed by looking at two scene: 1) Non-inverted Sator's retreat after Ive's team seizure of the turnstile; 2) Inverted Sator's lines eavesdropped by the Protagonist via bluetooth earbuds.

Yes, one of Sators henchmen goes out and steals the algorithm right before the protagonist inverts.

The protagonist inverts so now the thief, moving in reverse UNsteals the algorithm.

When TP comes out he quickly looks in the backseat of the car and notices the algorithm is there. Really subtle here. Great acting Denzy Junior and great directing Christy Noles

He drives all the way back to the part where the Sator lights him up. Literally, not figuratively like the last time.

At this point the algorithm is still travelling back all the way to the beginning of the heist, safe and secure and locked down in the transport truck moving backwards all the way back to Kiev.

At the end of the day. Not literally. Time moves forward due to the winds of entropy flowing forward so everything that we just talked about rewinds. It’s actually forwarding, but yeah. You know.

Algorithm is (again) in the car. The henchman UN-UN steals it and wham! Sator is your uncle.

Team Sator now has the algo to do with what they please.So of course they stick it in a turnstile and send it all the way back to the day of the big explosion in Sators old ‘hitting his workmate in the head with a shovel’ grounds.

They have a good reason why they didn't go through this in the movie because if they did this will complicate things, basically what happens, is once Sator knew where the algorithm is, he can let someone know and get it for him, but let's think about that for a moment, the protagonist can do the same thing since he's already in the past himself, he can unsend a text to cavalry, or unwrote a letter, or unsend a message to Neil or himself about the chase events and where the algorithm is, I guess they knew this will complicate things even further so they avoided showing it to us.

by the way, when the protagonist looks behind the seat he was looking for the keys because back then he wouldn't know that the algorithm is in there.

About the orange case, you're thinking about the inverted and uninverted Sator and protagonist at the same time, it doesn't work like that, I will only be talking about the inverted scene here, for the inverted sator, it will look like he's getting the orange case from the grass to the Mercedes car, this car is driven by an uninverted driver, on the back there's the inverted Sator and his inverted audi driver, they're getting the open orange case, closing it, then Sator throw it to the protagonist, crashing the inverted protagonist car, and then started counting backward while holding the gun on kate ...

• He already has the keys when he looks around in the car - otherwise how did he get the door open? (I think it's not actually shown, but the script says he finds they keys sitting on the front tyre, before he starts looking behind the seats.) Jan 23, 2021 at 8:33
• The car was push start, and it was open, that's what I thought, so why do you think he looks at the back seat? Jan 24, 2021 at 3:13
• Here's what's written in the script: "In the yard he spots the SAAB... he runs over, finds the keys sitting on the front tyre – [...] The Protagonist LOOKS in the glove box – NOTHING – LOOKS in the wheel well – NOTHING – the back seat – NOTHING. He gives up – starts the engine... pulls out, gently, feeling out the strange handling of the vehicle... " It doesn't say what he's looking for but it clearly states he finds the keys before that, and I think we have to assume he's looking for the algorithm. (I don't think we see the keys on screen though - they probably just cut that shot.) Jan 24, 2021 at 7:58