Armed with only one word, Tenet, and fighting for the survival of the entire world, a Protagonist journeys through a twilight world of international espionage on a mission that will unfold in something beyond real time.
In a twilight world of international espionage, an unnamed CIA operative, known as The Protagonist, is recruited by a mysterious organization called Tenet to participate in a global assignment that unfolds beyond real time. The mission: prevent Andrei Sator, a renegade Russian oligarch with precognition abilities, from starting World War III. The Protagonist will soon master the art of "time inversion" as a way of countering the threat that is to come.
After having a near-death experience, an unnamed CIA operative, known as the Protagonist, is selected to join the ranks of the shadowy government organization called Tenet: a group tasked with ensuring the survival of the human race. Entrusted with coming to grips with a terrifying, cutting-edge technology, and an imminent attack from the future, the Protagonist teams up with his cryptic new partner, Neil, following a faint trail of clues that lead to the villainous Russian oligarch, Sator. However, this is a race against time, and as the suffocating stranglehold of the invisible threat tightens, more and more, the future of our world is hanging by a thread. Can two agents working alone avert the impending Armageddon?
- In Kiev, Ukraine, an unnamed operative, a.k.a The Protagonist, assists in a CIA assignment to foil an opera siege and retrieve a stolen cache of plutonium. His mission also seems to be to rescue a man, which he does so with the help of a team with whom he blends in with SWAT teams. During the operation, the plutonium is found to be fake. Furthermore The Protagonist realizes that the opera was being bombed and so he collects the bombs to save the people. The Protagonist is at gunpoint by one SWAT member but is saved by a masked gunman with a red string on his back. The masked man appeared to be using a time-reversed gun. The Protagonist throws the bag of bombs away and the people are saved. He is then abducted and tortured until he bites on an apparent suicide pill before revealing any information.
Upon waking, the Protagonist learns the pill was a test of his loyalty. He also is told that his team didn't get clear. He is recruited into a secret organization, given only the information that the word "Tenet" and a cross-fingered gesture will "open many doors" for him. The Protagonist infiltrates a facility where he learns that in the future, technology has been developed that allows objects to have their entropy reversed and move backward through time. To demonstrate this, a scientist presents him with bullets that fire in reverse. The scientist believes that there is a war coming as objects are being streamed back in time from the future.
Tracking the metal from which the reversed bullets are made, the Protagonist infiltrates the compound of an Indian billionaire in Mumbai with the aid of Neil, a British intelligence agent. He learns that it is in fact the billionaire's wife, Priya, who knows what is happening. Priya tells the Protagonist that the time-reversing technology is under the control of a Russian arms dealer, Andrei Sator, who is in communication with the future.
The Protagonist meets Sir Michael Crosby who tells him that an explosion went off in a now-abandoned city in Russia known as Stalsk-12. The Protagonist learns from him that in order to get to Sator, he needs to approach his "practically estranged" wife Kat. The Protagonist meets Kat and they talk at a restaurant. Kat tells the Protagonist that Sator has her under his control due to a forged painting that she gave to him. She also mentions that she tried to love him again to see if he would let her go free but Sator gave her the option to stay or leave and never see her son again. She says she saw a woman dive off their yacht in Vietnam when they were on holiday. Sator's men arrive at the restaurant soon. The Protagonist manages to fight his way and escape but one of them drives away with Kat just as the Protagonist finishes the last henchman.
The Protagonist later tries to win the trust of Kat by retrieving the painting from a freeport at Oslo Airport. Neil goes first to inspect the situation and they plan to crash a cargo plane to start a fire to activate the lockdown procedure, allowing them to steal the painting. They take the help of Mahir, who crashes the aircraft and drops gold bars on the road as a distraction. During the operation, however, the Protagonist and Neil are attacked by two masked men, one inverted and one forward who emerged from a temporal stile in the pentagon. Both antagonists escape before the Protagonist and Neil are able to find out who they are. The Protagonist meets Priya who tells him that the two antagonists were the same person.
The Protagonist returns to Kat, asking for her help in meeting Sator. Kat arranges for the Protagonist to attend a dinner party, hosted by Sator, but the oligarch does not trust the Protagonist until he mentions "opera". The Protagonist, Kat, and Sator go sailing where Sator and the Protagonist are discussing about plutonium when Kat pushes Sator out of the boat. The Protagonist saves him and Kat is mad at him for that. Sator says he is in debt so he funds the Protagonist who offers to steal weapons-grade plutonium for him.
The Protagonist and Neil plan a heist on a highway and they succeed in stealing the plutonium, which is in an orange case, from an armored vehicle but they are interrupted by an inverted car. The car chases them until they see an inverted Sator holding a forward Kat at gunpoint in it. A crashed Saab on the road flips back and drives backward in between them. Sator signals the Protagonist to hand over the plutonium but the Protagonist hands over an empty orange case and throws the plutonium into the Saab. The Protagonist uncovers Sator and his gang's plot: they are operating a "temporal pincer movement" in which they move both forwards and backward in time, by means of entering a "temporal stile" following the operation and then moving backward through time.
At the "temporal junction", Sator shoots Kat and leaves with her before Neil calls for reinforcements and they arrive to secure the temporal stile. The Protagonist suspects them, questioning Neil about who these people are. Neil tells him they are Priya's men, a team led by Ives. The Protagonist follows Sator back through the temporal stile despite being warned not to, where he turns out to be the driver of the Saab. He puts a radio device on an empty orange casing on the road and waits for it to go back into a car. He follows it and it turns out Sator saw the plutonium flying from the Saab back into forward Protagonist's hands. He hears from the device that Sator had assembled the algorithm (the fake plutonium pieces) which are being taken to the hypocentre. In the chase, the Saab crashes with the inverted Protagonist inside it. Sator burns the car which turns into ice and manages to get hold of the algorithm piece off-screen. The Protagonist is rescued by Ives' team.
Sator is revealed to be dying from inoperable pancreatic cancer and has turned omnicidal, believing that if he is to die, he would prefer to spread death to all humanity. Sator is not looking for plutonium, but some future algorithm (9 pieces of the fake plutonium) that can cause the entropy "time direction" of the world to reverse. The algorithm will be created in the future by a future scientist as a way to turn back time since their future Earth is ruined by decisions made by present-day humans. Sator plans to use the algorithm as a doomsday device that will reverse entropy for the entire Earth, killing everything on it. He plans to return to a point in time when he was happy with Kat and then set off the device, which is connected to a dead man's switch linked to his heartbeat.
The Protagonist, Neil, and Kat follow Sator backward in time, travelling in a cargo ship container back to Oslo. The trio infiltrates the freeport art storage facility once again where they enter the temporal stile that allows Kat to move forwards through time again and have her gunshot wound healed. The Protagonist soon discovers he was, in fact, the unknown antagonist during their first operation at the freeport and hence has to fight his past self to go through.
The Protagonist meets Priya and wants her word that Kat will be safe. This is because she has seen too much of what they are trying to keep secret. Priya gives him her word. She also reveals to him that Tenet will be founded in the future. She says Ives has a team ready for the mission.
They travel further back in time, where a military operation is launched whereby the Protagonist and Neil attempt to retrieve the doomsday device from Sator's men from the future in Stalsk-12, while Kat is with her husband on his yacht, aiming to prevent him from killing himself before the doomsday device is retrieved. They operate in a temporal pincer movement where the red team moves forward covering the blue team's extraction and the blue team moves backward covering the red team's extraction. The Protagonist and Ives are on the red team while Neil is on the blue team.
Neil uses a temporal stile there to invert back to forward, halfway through the operation, to warn the Protagonist and Ives about a trap that he witnessed planted by Volkov - one of Sator's men. However, Neils efforts are in vain. The Protagonist and Ives enter the tunnel and get stuck in there. They go deeper and find the place where the doomsday device is monitored by Volkov who is behind a gate that is locked. They also see a member of the blue team dead beside Volkov with a red string attached to his bag. The Protagonist recognizes this unknown person from the opera siege. Sator talks to the Protagonist from the boat about his plan through a communication device in the tunnel. Sator then orders Volkov to shoot the Protagonist in the head when the dead body emerges, takes the shot and the gate unlocks. The Protagonist and Ives kill Volkov and retrieve the doomsday device. The blue team member closes the gate and goes back to the entrance.
Time is running out. Neil who has switched halfway, throws a rope through the hole on top of the tunnel and the Protagonist and Ives hold on as they are pulled up. Kat kills Sator on the boat. The explosion goes off but the world is saved. Kat realizes that she was the woman her past self had seen on the boat and dives into the water.
The Protagonist notices that Neil has a red string on his back and deduces that he was therefore the masked man who saved him during the opera siege and the blue team member who gets killed by Volkov. The Protagonist sheds tears as he knows his friend's destiny now. Neil reveals that he was hired into this operation in past by the future Protagonist and thus has known him for years. Neil tells the Protagonist that he'll see him at the beginning and goes back into the operation with the blue team.
The Protagonist then saves Kat from being killed by Priya after all of the film's events, revealing that it is his job to tie up loose ends and that he has been the leader of Tenet operations for two years in the past.