I am not going to cover the story line by line as there are many articles out there. I will just focus on the concepts and details that will help us understand the movie TENET.
The concept of perceiving time
We as humans currently do not completely understand time but eagerly want to (I hope so 🙂). It is theorized that time moves in one direction —-> FORWARD —>
Can it be wrong? The answer maybe yes, because right now we are unable to figure it out.
TENET is trying to convince us that we are perceiving time as moving forward whereas it can move forward (Yes forward!) even if we are moving backwards relative to first case. Totally confusing?
Let me explain, FORWARD or BACKWARD is a relative term and depends on where in time you come from. Lets take a example in which we think of time as a road with two deadends namely A & B imagine two people named Pranav and Vanarp walking in the opposite directions, Pranav is going from A to B and Vanarp is going from B to A. Here Pranav sees himself walking forward on the road of time and same goes for Vanarp as he sees himself walking forward on the road of time, whereas they see each other walking in the opposite direction (BACKWARD!). You see, the nature of time is subjective.
As a human, imagining myself moving backwards in time makes me feel confused, as the world around me is reversed and my intuition will no longer be valid.
The movie seems a chaos unless…?
In the far future a scientist develops an Algorithm that can reverse an object’s entropy and thus the object can the move backwards in time from our perspective but from the object’s perspective it is still moving forward. The scientist then realizes that the algorithm is too dangerous and if misused can destroy our existence. So, she decides to split it and bury the pieces in the safest places of the past (Nuclear facilities).
The Protagonist is in search of the supplier of the inverted objects (Sator). Along the quest he meets Priya (A weapon dealer’s wife), she knows that Sator is getting those objects inverted from future humans.
Sator has control over his wife Kat using a art piece and now the Protagonist is trying to use this situation to get closer to Sator. In the movie Sator is not just an arms dealer but he is the one having contact with the future humans. Sator wants to assemble all the pieces of the Algorithm and bury them safely for the future humans to find it.
When the Protagonist meets Priya again, we get to know that the Plutonium 241 was actually one of the pieces of the Algorithm that Sator is trying to collect. To make the job easier Priya is planning to let Sator assemble the algorithm and then steal it.
On the yacht, Sator talks about the future; the oceans have risen and the rivers have dried up because of human actions. So, the future humans want Sator to assemble all the pieces of the algorithm and bury it safely. Many many years later, the future humans can then dig it up and reverse everything to erase the past. Now the whole plan to make Sator believe that the algorithm is buried safely and the future humans can use it.
The Grandfather paradox is driving the actions of the Protagonist. The paradox is well explained by Neil when he was traveling to Oslo.
The grandfather paradox is a paradox of time travel in which inconsistencies emerge through changing the past. The name comes from the paradox’s description: a person travels to the past and kills their own grandfather before the conception of their father or mother, which prevents the time traveller’s existence. Despite its title, the grandfather paradox does not exclusively regard the contradiction of killing one’s own grandfather to prevent one’s birth. Rather, the paradox regards any action that alters the past, since there is a contradiction whenever the past becomes different from the way it was.
He also says, the future humans believe that killing all the past won’t affect the future regardless of the what will really happen (Their belief is driving their actions).
Temporal Pincer Movement and the Turnstile
In the armed forces a pincer movement is used to confuse the enemy by coordinating an attack from different directions. In a temporal pincer movement the temporal stands for time and there are only two possible directions for an attack using time (one forward and one backward as we can imagine). The turnstile is just a tool that helps us reverse our direction in time.
Throughout the movie we get to see two prominent pincer movements while the whole movie is also a third temporal pincer.
The first temporal movement is the exchange of so called Plutonium 241 between Sator and the Protagonist. Half of Sator’s team is moving forward in time and the other half are moving opposite to them. Sator is standing near the Turnstile and the team which moving forward in time is reporting each and every detail of the exchange to Sator. Once the exchange is complete Sator can use the turnstile and move back in time and use the knowledge that he gained from his first team to take part in the exchange. It is important to realize that reverse Sator can take part in the exchange but can’t manipulate it because the events will happen as it was and is supposed to happen because reverse Sator was going to participate in the exchange anyway (I know this one is a little counter intuitive). You get a clearer view if you watch the movie Predestination.
In the end we also see a temporal pincer movement carried out by the red and blue teams. The blue team gains knowledge of the events and then the red team plans accordingly.
Throughout the movie the Protagonist and Neil are in a third temporal pincer movement. Near the end of the movie, the Protagonist asks (to Neil) “Who recruited you?” and he replies “You (The Protagonist) recruited me and this is the end of a beautiful friendship”.
That means Neil was recruited by the future version of the Protagonist and the Protagonist is just half way in the Temporal Pincer movement of his whole life. At last the Protagonist stops Priya from killing Kat and now we know for sure that the whole TENET was planned by the future Protagonist and he sent Neil to help his past self.
No one can say for sure but Neil could be Kat’s son! (Yes this is how a Nolan’s movie ends 😂)