Oscar Lau’s review published on Letterboxd:
One of the earliest visual tricks utilized in films is the reserve motion, it has been adopted since (perhaps more prominently in) the silent era. An action that is filmed is shown backward, creating an illusion that the phenomenon of cause-and-effect is reciprocated, or a perilous situation (e.g. nearly hit by a train) while situating the actors in guaranteed safety. It’s the magic optical effect that bends our perception of time without us even realizing it.
In Tenet, Christopher Nolan’s latest action-packed sci-fi espionage, action is divided into foreword and backward according to our perception of time and the comprehension of the causal effect. A gun’s trigger is pulled, then a bullet is ejected from the barrel in a trajectory against the resistance of air and the gravitational pull and finally stops until its kinetic energy is completely transferred into heat, light, thus creating the ‘wound’ on the subjects it hit. Ten minutes into the film’s first action set-piece, a hostage situation in an audience-filled opera house, an unnamed CIA agent (John David Washington) known as the Protagonist would witness a time-inverted phenomenon. A bullet is ejected from a bullet hole, piecing an enemy’s shoulder before entering the barrel of the gun a masked man is holding.
This is the audience’s first taste of the reverse motion, the effect of an ‘inverted’ entropy singled out on a specific object, which is the bullet. As the bullet goes against the law of physics we have learned from daily life, our mind would be led by Nolan in a simultaneous forward and backward motion, which is further sub-divided by the camera’s perspective/the subjective perception of time. Hence, when the Protagonist digs deeper into the mystery surrounding an organization called Tenet and the threat of world destruction steered by people from the future, we would experience the vertiginous confusion on the so-called reality. Particularly when a 'time machine' with two revolving-door entrances occupying two rooms separated by a glass window is introduced, the direction of motion and time would be the major source of our perplexity. Soon we would experience the world around the Protagonist going ‘backward’ instead.
Nolan is a master of setting up unique rules in his cinematic universe, from the split narrative mechanisms (one in chronological order, one in reverse order) in Memento, to the dream world principle applied during the heist within multilayered dreams in Inception, he has an affinity to rearrange and inflate/stretch the temporal, and sometimes the spatial, space. But he fails to be an eloquent storyteller. The expositions of the established rules in Tenet are not least puzzling. Not that you need a major degree of Physics to comprehend the plot (frankly it would be extremely helpful), but when the majority of my thoughts are engaged with figuring out when, where, who, and how, I don’t think I would give a damn of the outcome.
By displaying the same fight in two perspectives, and the same interrogation scene through the two point-of-views in the two-room after the time machine is introduced, Nolan illustrated four types of actions in total according to the subjective flow of movement and the objective flow of time in Tenet: 1. forward motion/forward time (the usual action as we see in a linear narrative); 2. backward motion/forward time (e.g. the reverse bullet); 3. forward motion/inverted time (through the subjective point of view of the Protagonist, his action is ‘forward’ but actually he’s going back in time, thus he sees the birds are flying backward); backward motion/inverted time (the flying-backward birds in example 3, which is equivalent to 2 in concept). In the climactic battle, the perspectives are shifting back-and-forth between the Protagonist in normal time flow and the handler (Robert Pattinson) in inverted time, and we witness all four types of actions in full display. In conclusion, it’s utter chaos.
But let’s ignore the Physics and focus on the basic, the characters. As I said before, I hardly care about the Protagonist, his relationship with his handler Neil is quite peripheral, only partly redeemed by the twist at the end. But it feels almost like a cheat, and his role is hardly intriguing. The only character who strikes as ‘relatable’ is Kat (Elizabeth Debicki). Her marriage with the abusive husband Sator (Kenneth Branagh) evolves from a side plot into a cathartic climax alongside the final soulless battle on the Protagonist’s side saves the third act. Sator is an unforgettable antagonist, his temperamental behavior and his connection with the ‘future’ are the major threats amid the film, but can't change the fact that the character is a caricature.
Narratively, calling it convoluted is an understatement. The Protagonist traveling from places to places, chasing after different targets and mostly MacGuffin (the ultimate MacGuffin is the Algorithm, the world-destruction device), running towards the future or going back in time, I have to admit it’s quite fun to watch, albeit causing many headaches simultaneously. I would love to go back for a rewatch (not using the device) after learning the ending, maybe I would have a better grasp on the characterization of the Protagonist. But since Tenent can't evade the grandfather paradox, the result is "whatever happened, happened", I won't change the fact that this film is needlessly complicated. Perhaps Tenet is Nolan’s worst film, it definitely has its (many) flaws, but my appreciation of the boldness of the story and its originality prevails ultimately. And most importantly, it’s an eloquent reason to go back to theater after COVID-19. Yes, humanity still has a future.