Plot

An undercover MI6 agent is sent to Berlin during the Cold War to investigate the murder of a fellow agent and recover a missing list of double agents.

The crown jewel of Her Majesty's Secret Intelligence Service, Agent Lorraine Broughton (Theron) is equal parts spycraft, sensuality and savagery, willing to deploy any of her skills to stay alive on her impossible mission. Sent alone into Berlin to deliver a priceless dossier out of the destabilized city, she partners with embedded station chief David Percival (James McAvoy) to navigate her way through the deadliest game of spies.—Focus Features

Just before the fall of Berlin's wall in 1989, the lethal MI6 secret agent, Lorraine Broughton, is sent to Cold-War Germany to meet her contact, the station chief, David Percival, after the murder of a fellow undercover agent. Intent on recovering an invaluable microfilm containing the list of names of every British spy, Lorraine must do battle with endless waves of hard-as-nails KGB agents and unrelenting henchmen, in the bowels of a city at boiling point. Under those circumstances, as both sides want the list desperately, whom can Lorraine trust?—Nick Riganas

In November 1989, just days prior to the collapse of the Berlin Wall, MI6 agent James Gascoigne is shot and killed by KGB agent Yuri Bakhtin, who steals The List, a microfilm document concealed in Gascoigne's wristwatch that contains the names of every intelligence agent (on both sides) active in Berlin. Ten days later, Lorraine Broughton, a top-level MI6 spy, is brought in to be debriefed by MI6 executive Eric Gray and CIA agent Emmett Kurzfeld about her just-finished mission to Berlin. The plot jumps between the debrief room and flashbacks to Lorraine's time in Berlin..

London, November 1989. Beautiful and lethal, MI6 agent Lorraine Broughton is being interrogated by her superior Eric Gray, and against her objections CIA agent Emmett Kurzfeld, it a debrief concerning a just concluded mission in Berlin "gone wrong" in certain respects in what ended up being the approach to the fall of the wall. Murdered MI6 agent James Gascoine was supposed to have a comprehensive list of secret agents on both sides given to him by a Stasi agent named Spyglass, that list getting in the wrong hands i.e. the KGB which would tip the balance of the Cold War. In Gascoine's death, the list had gone missing, Broughton dispatched to Berlin undercover to recover the list from who they believe currently has it, a KGB agent named Yuri Bakhtin, she to work with MI6's Berlin section chief David Percival, who has immersed himself in the bohemian Berlin lifestyle both as a cover but also as a personal choice. Broughton felt that there was someone tipping off the KGB as she believed her cover was blown as soon as she arrived in Berlin, which leads to the reason for her objection of Kurzfeld being in the meeting in she not wanting to divulge information that he should perhaps not know: that she had a secondary mission in Berlin, namely to discover the identity of a mole who had long been giving MI6 problems, that agent going by the code name Satchel. She didn't know if Satchel was the source of the leak of her identity to the KGB and/or the young, mysterious woman she noticed following her ever since her arrival in town. With regard to the list, she learned that Spyglass himself could be as important an asset to the West as the list, he wanting to defect however with conditions.—Huggo

In 1989, before the collapse of the Berlin Wall, MI6 agent James Gasciogne (Sam Hargrave) is shot and killed by KGB agent Yuri Bakhtin (Johannes Johannesson), who steals the List, a piece of microfilm concealed in a wristwatch that contains the names of every active field agent in the Soviet Union. Gasciogne believes that Satchel betrayed him and gave up his cover to the Soviets. The list was provided to Gasciogne by a Stasi informant code-name Spyglass (Eddie Marsan), who was promised immunity by the MI6 in exchange for the List. The list can extend the cold war for another 40 years, so all governments are after it and Yuri is still in Berlin.

Ten days later, Lorraine Broughton (Charlize Theron), a top-level spy for MI6, is brought in to be interrogated by MI6 executive Eric Gray (Toby Jones) and CIA agent Emmett Kurzfeld (John Goodman) about her mission to Berlin. C (James Faulkner) is the head of MI6. Before the debrief starts, Lorraine asks for Kurzfeld to be removed, but Eric denies the request. The rest is in flashback.

The day after Gasciogne's death, Lorraine is dispatched to Berlin by Eric and C to recover the List and assassinate Satchel, a double agent who has sold intelligence to the Soviets for years and who betrayed Gascoigne. Lorraine is chosen for the assignment as her Russian is excellent. The list is supposed to contain the identity of Satchel, which is why MI6 is interested in it.

Meanwhile Spyglass contacts David Percival (James McAvoy) MI6 top man in Berlin to inform him that he has delivered the list to Gasciogne. Percival refuses to take Spyglass since Gasciogne didn't show up and he still doesn't have the list. Spyglass says that he has the list memorized. Percival operates in East Berlin, but travels to West Berlin using the sewer network under the boundary wall.

When Lorraine arrives in Berlin, she is immediately ambushed by KGB agents working for arms dealer and KGB associate Aleksander Bremovych (Roland Moller), but is able to escape thanks to her main contact, agent David Percival, showing up to help. Percival says that he has never met Spyglass. Bremovych is also looking for Bkahtin for the list and knows Bakhtin is trying hard to sell it.

After failing to find any immediate leads, Lorraine searches Gascoigne's apartment and discovers a picture of him and Percival and is then ambushed by the West German police. She realizes only Percival knew she was going to the apartment and begins to suspect him of being Satchel. When Lorraine visits a restaurant mentioned by the KGB agents, she encounters Bremovych but is "saved" by novice French agent Delphine Lasalle (Sofia Boutella), a naive French agent. Although initially suspicious of Lasalle, Lorraine later enters into a relationship with her. Lasalle suggests that they should work together.

Percival, having tailed Lorraine, surveys a watchmaker she visited and spots Bakhtin. Lorraine is informed that Satchel's identity has been compromised.

Bakhtin declares his intention to sell the List to the highest bidder. Percival, having been tipped off, kills him and takes the wristwatch from which he discovers who Satchel is. Percival meets Lorraine & now informs her that Spyglass has memorized the list and wants to defect.

Lorraine is upset that Percival did not reveal this before, else she would have prioritized the extraction of Spyglass. The same night Percival called Eric and told him that he had the list and knew the identity of Satchel. This was not known to Lorraine. Percival meets with Bremovych and offers Satchel's identity "to keep the balance", and tips him off about their plan to extricate Spyglass. Lasalle covertly photographs the meeting.

Percival offers to escort Spyglass, and his family across the border to West Berlin. Lorraine offers to help & make her own arrangements. Percival has shooters on top to take out Spyglass, but Lorraine hides herself and Spyglass behind umbrellas to thwart the shooters. However, Pervical shoots Spyglass and tips off Bremovych's men, and despite Lorraine's best efforts, Spyglass is killed.

Lorraine makes it to West Berlin and realizes Percival has planted a bug in her coat. She tells Lasalle. It turns out that Lasalle was following Lorraine on Percival's instructions. But now Lasalle knows that Percival has met Bremovych & threatens him. Percival goes to Lasalle's apartment (Percival warns her that she doesn't know who she is dealing with (referring to Lorraine)) and kills her, fleeing as Lorraine arrives moments later. Lorraine discovers Lasalle's photographs and realizes Percival has The List. Percival attempts to flee, but Lorraine intercepts, kills him, and takes The List.

Percival then goes to Lasalle's apartment and kills her to cover his own tracks. When Lorraine arrives too late to save her, she discovers the photographs taken by Lasalle proving Percival to be Satchel. As Percival burns his safe-house and attempts to flee, Lorraine tracks him down, kills him, and takes the List. Lorraine reveals that he had met Bremovych as the real target that day was not Spyglass, but Lorraine. Percival wanted the KGB to eliminate Lorraine. He knew that Spyglass was a liability to everyone and thus had to eliminated as well and that Lorraine was the real Satchel.

Later, Lorraine is debriefed by MI6 executive Eric Gray and Emmett Kurzfeld. While there, she discovers Percival had told Gray he had The List and he was "very close to Satchel". She presents Lasalle's photographs and doctored audio recordings, which paint Percival as Satchel. She denies knowing The List's whereabouts, leaving MI6 no choice but to close the case.

Three days later in Paris, Lorraine, now speaking in Russian, meets with Bremovych, who addresses her as "Comrade Satchel". Bremovych, having learned from Percival there is more to Satchel than he had previously known, orders his men to kill her. Lorraine kills his henchmen. Speaking with an American accent, she tells Bremovych she always fed him misinformation to manipulate the KGB and kills him.

She and Kurzfeld return to the United States with The List. In their conversation, it is implied Lorraine is actually a triple agent and had been working for the CIA all along.