I’ve watched “Tenet” two times and I think I understand most of it. Maybe.

A character in the film actually cautions viewers not to think about it too much. I.e. focus on the visual acrobatics and the bizarre majesty of reverse hand-to-hand combat, but don’t tax your poor little brains with the specifics.

Well, I reject that. My poor little brain lives for trivial specifics.

I’ve been able to piece together most of the story based on my own viewing and lots of Google queries like “Is Neil stuck in a time loop?” and “What happens at the end of Tenet?” and “What did linear time do to Christopher Nolan and why does he hate it so much?”

But there are still a bunch of things that haunt me:

Is everyone in the film stuck in a time loop, or is it just certain characters? And does the loop ever end?

Who originally built the turnstiles and when were they constructed? Also, who handles maintenance on these things?

How many people know what the turnstiles can do? It seems like a lot of folks are in on the secret.

Why is Sator chosen by the future people to be their minion? And who made that choice? (There’s an off-hand comment that the fall of the Soviet Union made for easy-ish access to nuclear weapons, which are somehow connected to the inversion process. But why was Sator picked over other people living in the same place at the same time?)

What is Sator’s motivation? Is it really “if I can’t have it neither can you”?

And speaking of motivation … do the future people believe that wiping out the past will save their present? Do they think that by inverting time they’ll flow merrily backwards with no repercussions (that seems … naive)? Or do they want to take revenge on the people of the past while ending their own horrible existence?

How, exactly, does Sator’s death activate the algorithm? Did he manually set a timer or would the thing go off if he slipped in the shower?

We know that if an inverted person touches their non-inverted self, bad things happen. But can two versions of the same person–both either inverted or uninverted–exist in the same time flow? The answer to this appears to be “yes” because one version of Kat dives from Sator’s yacht and her other version sees the dive. But can these two versions continue to live in the same timeline without messing everything up? And how does that affect tax returns?

What happens if you invert and then need to use the bathroom? Does it do what it seems like it might do? (And why did I ask this?)

Helpful links: I found these write-ups to be useful as I went down the “Tenet” rabbit hole: