*CUT TO THE CHASE*
NOTE: This spoiler was submitted by Jeremy
Ibiza, Spain - Mitch Rapp (Dylan O'Brien) is making a video on the beach with his girlfriend Katrina (Charlotte Vega). He pulls out his mother's engagement ring to propose to her. Katrina accepts. Mitch runs to get drinks at the bar, accompanied by applause from those that saw the proposal. Moments later, a team of radical jihadists come up on the shore and begin to shoot at the beachgoers. Mitch runs to Katrina, but she is shot dead by the jihadist leader Adnan Al-Mansur (Shahid Ahmed) before Mitch can reach her.
18 months later, Mitch lives alone in an apartment. He's been taking kickboxing lessons to build his physique, but his impulsiveness gets him kicked out too often. Mitch chats online with Mansur in the hopes of infiltrating his cell and killing everyone responsible for Katrina's death. Mansur asks Mitch questions about the Islamic religion. Unbeknownst to either of them, they are under surveillance by CIA Deputy Director Irene Kennedy (Sanaa Lathan).
Mitch is invited to meet with Mansur at his hideout. Mansur is under the impression Mitch wants to join his cell. After having him bound to a chair, Mitch plots his escape and subsequent slaughter of the cell, only for a Special Forces team to burst in and kill Mansur and his men first. Angry, Mitch grabs a knife and starts stabbing Mansur's corpse before getting pulled off.
Mitch is in an interrogation room where he meets Kennedy. She knows about Mitch's past, including what happened to Katrina and that he lost his parents in a car accident when he was 14. All Mitch has on his mind is revenge. Kennedy decides to send Mitch to Orion, a black ops training program run by former Navy SEAL/Cold War vet Stan Hurley (Michael Keaton).
Kennedy drives Mitch to Hurley's base for him to start training. Hurley immediately thinks little of Mitch as a recruit. When the actual training begins, Hurley shows the recruits certain methods of combat, a particular throat kill, and that if they are on the verge of capture, they must put a bullet in their heads. They also go through a training exercise to take out targets in a fake department store, but Mitch gets too carried away by repeatedly shooting targets. Another one involves simulated targets, and Hurley gets into Mitch's head by placing Mansur in front of him, despite not being an assigned target.
We move to a group of men trying to make a deal over a piece of weapons grade plutonium stolen from a Russian nuclear facility. The main buyer is a man known only as "Ghost" (Taylor Kitsch). Two police officers knock on the door of their van. Ghost invites them in and kills them before killing the other two buyers. He then shoots at police in the crowd outside before disappearing. Hurley sees the news and recognizes Ghost as one of his former proteges that was believed to have been killed in an airstrike after going rogue.
Kennedy has Hurley send his team to Turkey to catch Ghost's prospective buyer. They meet with their operative, Annika Ogden (Shiva Negar), who poses with Mitch as his wife as they try to get intel on the main buyer, a man named Sharif (Khalid Laith). Unfortunately, the team gets made in a restaurant where one of their own is stabbed to death, and they lose Sharif before they can get to him.
Mitch follows Sharif to his hotel after beating information out of one of Sharif's goons. Mitch sneaks into his hotel room, leading to a shootout between Sharif's goons and Hurley's team once they join Mitch. Mitch finds Sharif in his room, begging for mercy. Mitch briefly sees Mansur in his place, prompting him to kill Sharif and then take his laptop. Hurley chews him out for acting against orders, but Mitch thinks he did what he was supposed to do. Hurley then shows Mitch the video he recorded of Katrina before her death, making Mitch angry. Hurley subdues him and reminds him to never make it personal.
The team heads to Rome where they try to gather info on a physicist who can make a weapon from the plutonium. While staying at a hotel, Annika tends to one of Mitch's wounds. She casually states that they will get Ghost. Mitch follows her since he never name-dropped Ghost. He fights Annika in the bathroom and accuses her of being Iranian Intelligence while holding her underwater until she confesses.
Annika is brought in for questioning, and it turns out she really is a mole for the Iranian Intelligence. However, she explains to Hurley that she was simply trying to prevent Iranian hardliners from acquiring the weapons that could potentially be used against Israel to ignite a war.
Hurley meets with his contact, who is also Annika's uncle, to discuss her and the issue surrounding the plutonium. Moments later, Ghost infiltrates their meeting, kills the contact, and captures Hurley.
Ghost tortures Hurley into giving up his team by removing his fingernails with pliers. Hurley refuses to talk. He refers to Ghost by his real name, Ronnie. Ghost then drops a spark plug into the water bucket where Hurley's feet are. When Ghost's hardliner associates come for the weapon, Hurley tells them Ghost is playing them. Ghost shoots and kills the hardliners and makes off with the weapon.
Two Mossad guards take Annika from the CIA safe house, but Mitch finds them and rescues her before going to get Hurley. Mitch and Annika chase Ghost through the tunnels, but Ghost grabs Annika and holds her at gunpoint. Annika grabs the gun and shoots herself in the head. Ghost heads off with the weapon onto a boat.
Hurley determines that Ghost is making a last stand at sea with the weapon. The Sixth Fleet gets their ships ready when they learn about the impending attack. Mitch goes after Ghost and fights him on the boat. Ghost nearly overpowers Mitch and stabs him, but Mitch gains the upper hand and kills Ghost with the knife attack that Hurley taught him. Mitch then rides the boat out to sea where Hurley orders him to drop the weapon into the water. Mitch climbs up the chopper that Hurley is in, just before the bomb detonates underwater, creating a gigantic sinkhole that nearly swallows the Navy's ships, but everyone is ultimately saved.
Hurley returns to the U.S. to get treatment for his wounds. In the hospital, he sees a news report of one of the hardliners, General Rostami (Joseph Long), being considered the frontrunner to win the presidency in Iran. His televised speech promises to destroy America. We then see Rostami getting into an elevator. He turns around to see Mitch standing behind him, smiling.