Mission: Impossible – Dead Reckoning Part One (2023)

IMF agent Ethan Hunt's new mission is to retrieve half of a key from his ally Ilsa Faust, on whom IMF has placed a bounty. He travels to the Empty Quarter in the Arabian Desert, briefly reunites with Ilsa and tells her to lay low. Back in the US, Ethan infiltrates a meeting of the Community, where officials of various intelligence agencies, including former IMF director Eugene Kittridge and DNI Denlinger, discuss an experimental AI called the Entity. Originally designed to sabotage digital systems, the Entity went rogue, expanded to potential sentience, and infiltrated all major defense and military systems and intelligence networks. Major powers are racing both to prevent sabotage and to gain control of the Entity.

 Believing that the Entity poses too great a threat to humanity, Ethan decides to destroy it. He and his teammates Benji Dunn and Luther Stickell travel to Abu Dhabi International Airport to intercept the holder of the other half of the key. Ethan evades Community agents as well as Gabriel, an Entity liaison with ties to his pre-IMF past, before losing the half-key to professional thief Grace. Meanwhile, Luther identifies a piece of baggage containing a nuclear explosive sent by the Entity; Benji narrowly defuses it only to find it empty. Rattled by the Entity's seeming precognition and the appearance of Gabriel, Ethan goes after Grace alone. In Rome, Ethan tracks down Grace before Community agents and Gabriel close in. After a lengthy chase, Grace escapes again, but Ethan is reunited with his team and Ilsa.

 With Benji and Luther providing support, Ethan and Ilsa infiltrate a party held by arms dealer Alanna Mitsopolis in Venice, hoping to find the buyer for the complete key and learn its true purpose. Grace delivers the half-key to Alanna, and Ethan dissuade a fearful Alanna from selling the key. Gabriel states that one of Ethan's comrades, either Ilsa or Grace, will inevitably die that night. The team scatters, with Ethan subduing but sparing Gabriel's subordinate Paris. Gabriel knocks Grace out and kills Ilsa before Ethan can intervene, devastating Ethan. A remorseful Grace is convinced to join Ethan's team, and they prepare to board the Innsbruck-bound Orient Express where Alanna will meet the buyer. Luther leaves for an off-grid location to investigate isolated traces of the Entity in his hard drive. On the train, Gabriel kills the engineer and fireman, and destroys the throttle and brake. He meets Denlinger, who proposes an alliance between himself and the Entity.

 Denlinger explains that the complete key unlocks the chamber housing the computer of Sevastopol, a Russian submarine which was sunk by its own torpedo in the start of the film. An early version of the Entity infected the system with the task of sabotaging the submarine's stealth capability, but it instead tricked the Sevastopol into destroying itself. This early version is still on the submarine, and whoever can access it can devise the means to either control or destroy the Entity. Gabriel kills Denlinger and attempts to kill Paris to ensure that only he knows about the key’s purpose. Impersonating Alanna, Grace brings the complete key to the buyer, who turns out to be Kittridge. Though tempted to betray Ethan for a reward and protection for herself, she sides with him, pickpockets the key back and flees.

Ethan parachutes off a perilous cliff onto the train to save Grace, but Gabriel gets the key. Ethan overpowers Gabriel but does not kill him. Gabriel escapes the trains and initiates a countdown to detonate the bridge ahead. Grace and Ethan detach the locomotive and save the passengers. Just before they are about to plunge down the broken bridge, they are saved by Paris. Paris informs Ethan of the Sevastopol before falling unconscious due to her injuries. As Ethan flees the train, Grace informs Kittridge that she has chosen to join IMF. Ethan meets with Benji and they drive off with the key that Ethan pickpocketed during his fight with Gabriel.