The Ending of 'Tenet' Explained

This article is a massive spoiler for Tenet so proceed at your own risk. But to understand the risk you're taking, you're going to need this article. I saw Tenet last week and while the set-piece and cinematography are fun, the story leaves you in the dark. A lot. 

Like there were a ton of times I was so lost I just had to power through into the next scene and hope I could fill in the blanks later. 

So, let's go through Tenet and try to answer those unexplained questions the best we can. 

Dissecting the plot of Tenet

Tenet is about a war with the future and the past. Basically we are trying to stop the present from being nuked from the future—but it's not a real nuke. It's a series of 9 cubes that when put together will reverse the entropy of time. This weapon is called the algorithm.

I told you it was hard to follow! 

The person behind this madness is named Sator, he has cancer and is dying. He's so mad about dying while being a billionaire, that he is uniting these cubes that will end existence so the world can't go on without him. 

At the beginning of the movie, a guy we know only a Protagonist is recruited to figure out what Tenet is by the CIA. Protagonist meets Clémence Poésy's scientist, who informs him that at some point in the future, technology is invented that can reverse the entropy of people and objects.

That means it creates chaos in a system that usually flows one direction. 

The big worry is that if you have an inverted nuke, it would create endless chaos and destroy the world. 

But for the Protagonist to figure out who has the cubes, or will have the cubes, he has to follow some inverted bullets all over the globe. The Protagonist tracks these bullets to Andrei Sator (Kenneth Branagh) and uses Sator's wife Kat (Elizabeth Debicki) to initiate a meeting in order to find out who Sator is working with and why he wants to blow up the world. 

He's able to track down Sator via his wife, and some exploration all over the world. 

So, why would anyone in the future be cool with helping destroy the world? 

Well, in the future, everything is destroyed. There's un unknown agency working with Sator to kill everyone in the past because the people in the future believe that reversing the entropy of the Earth will prevent climate change—yeah I missed that in theaters. So, with no other choice for their survival, they're willing to destroy their ancestors and threaten their own existence with the grandfather paradox, to make sure they can make it out on the other side. 

Along the way, a guy named Neil (Robert Pattinson) joins in the Protagonist's efforts. He always seems to know what's coming next in this story, and we think he could be a double agent. In fact, there are times where out characters cross over timelines and Neil never mentions it to Protagonist. 

This all comes to a head in a firefight at the end of the movie. 

The Ending of Tenet Explained

So at the end of the movie, our Protagonist is going to storm this old place where Sator grew up and where he plans to execute the algorithm, thus bringing to fruition the end of the world. The forces of the present have been split into two teams, blue and red. 

The red soldiers are traveling forward through time. The blue soldiers are the exact same soldiers, who start their attack 10 minutes in the future but are traveling backward through time.

They are fighting a closed city where the Algorithm is stored. These two teams participate in the operation to stop the detonation. The plan is to set a timer, the red team 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.

Once the bomb goes off it should stop the use of the algorithm. 

As they attack, we see Protagonist uses someone with a red string on their backpack as a human shield. After using that person he is able to steal the algorithm so it cannot be turned on to destroy the world. 

Later, we see that the red string on Neil's backpack, when he reveals that he was recruited by the Protagonist in the future—it turns out Protagonist is actually the head of Tenet. And will be the person who not only recruits Neil but also recruits himself on this mission. 

Neil is simultaneously the guy who dies in the final battle, alive in the present, and a guy who saves Protagonist in the past during the opera raid. 

There's even a theory that Neil is Kat's son, but from the future, time-traveling back to help. 

Either way, at the end of the movie, Neil, Protagonist, and Ives (a military guy played by Aaron Taylor-Johnson) all take 3 cubes of the algorithm and agree to disappear and bury them. Protagonist then travels to London to save Kat from arms dealer Priya, who believes she must tie up loose ends since she was dealing with Sator.

Protagonist kills Priya, finally realizing he will go back in time and found the secret organization Tenet. Which is how this movie started. 

Okay...I'm still lost - Explain the Tenet meaning...

I know this was a lot, but it's what happened. I only saw the movie once, but if you read the wikipage, a lot of people agree with this basal summary. Supposedly Nolan took more than 5 years to write the screenplay after deliberating about Tenet's central ideas for over a decade. This is admirable as a storyteller. 

But the movie felt like it had a ton of scenes cut out. I wonder if the originally reported 3+ hour-long film has a lot more explanation. 

I think the Director's Cut of this movie could be really meditative, and I look forward to seeing it. Right now, it took me a few hours to piece together my thoughts. While needing to see it again, Tenet definitely lives up to the hype of being extremely dense and moving so fast that you feel like it can be hard to catch up. 

But maybe that's the point? 

Got your own Tenet theories? 

Let us know in the comments.