Plot

A British diplomat travels to Munich in the run-up to World War II, where a former classmate of his from Oxford is also en route, but is working for the German government.

Based on the international bestseller by Robert Harris. It is Autumn 1938 and Europe stands on the brink of war. Adolf Hitler is preparing to invade Czechoslovakia and Neville Chamberlain's government desperately seeks a peaceful solution. With the pressure building, Hugh Legat, British civil servant, and Paul von Hartmann, German diplomat, travel to Munich for the emergency Conference. As negotiations begin, the two old friends find themselves at the center of a web of political subterfuge and very real danger.—Netflix

In 1932, friends Hugh Legat (George MacKay), Paul Von Hartmann (Jannis Niewöhner) and his girlfriend Lena (Liv Lisa Fries) celebrate their graduation from Oxford University. Hartmann insists they visit him in Munich to experience the "New Germany".

Six years later, Legat works as British prime minister Neville Chamberlain's (Jeremy Irons) secretary as Europe is on the brink of war. He is married to Pamela Legat (Jessica Brown Findlay). Chamberlain strives to obtain peace with Adolf Hitler (Ulrich Matthes) at any cost, even if that means allowing Germany to seize control of the Sudetenland from Britain's ally Czechoslovakia. But Chamberlain's talks with Hitler break down and Hilter plans to invade Sudetenland the very next day. Hugh works for his boss Sir Osmund Cleverly (Mark Lewis Jones), under the office of the PMO. Chamberlain remembers from a speech given by Hitler that he considers Mussolini as his friend. Chamberlain believes it is his duty to do absolutely everything in his power to avoid war. Chamberlain writes to Benito Mussolini in an effort to halt military action; it seemingly works (at the very last minute Chamberlain receives word (while he was addressing the house) that Mussolini has intervened) and Hitler agrees, inviting Chamberlain and French prime minister Édouard Daladier to Munich for a conference.

Hartmann meanwhile works as a translator in the Foreign Office in Berlin while secretly plotting with a Wehrmacht general in an effort to overthrow Hitler if top army officials agree to arrest him and seize control. The general believes this cannot be accomplished unless Hitler is allowed to invade the Sudetenland, while Hartmann doubts the collective resolve of the generals. Now with the conference, Hartmann is sure that Chamberlain will sacrifice Sudentenland to prevent war. Hitler would not need to invade and thus he would not be arrested. Hartmann is given a stolen document by his lover, Helen Winter (Sandra Hüller), that indicates Hitler intends to conquer Europe. Hartmann and the others reconvene and agree that getting the information to Chamberlain while he is in Munich is their best option (so Chamberlain doesn't make the deal and Hitler is forced to invade); Hartmann reveals he has a trusted former classmate, Legat, who can likely help. Legat is approached by Sir Horace Wilson (Alex Jennings) and a top MI6 official regarding the document in Hartmann's possession and agrees to help obtain it despite the dangers associated with espionage.

Legat remembers how Hartmann was rabidly pro-Hitler when he visited him in Munich few yrs ago. Legat convinces Chamberlain to bring him with to Munich under the guise of being a translator. Hartmann boards Hitler's train to Munich and hides the document and a pistol in the bathroom, soon discovering his roommate is a childhood friend named Franz Sauer (August Diehl), who has become a Schutzstaffel officer. Sauer becomes suspicious of Hartmann, who catches him rummaging through his suitcase in the train. Hartmann meets with Hitler, who chastises him for his Oxford education.

In Munich, Legat and Hartmann reunite, a flashback reveals they had a falling out in 1932 after a heated verbal argument related to Hartmann's then-support of Nazism. Legat agrees to take possession of the document, but insists Hartmann himself present the argument to Chamberlain that he should not sign the Munich Agreement. Legat and Hartmann meet with Chamberlain, who scoffs at the idea of not signing the agreement based on vague German military plans for a coup and refuses to take action. Chamberlain signs the agreement with Hitler shortly thereafter. Legat promises Hartmann to take the document to London and continue to press the issue. Later that night, Hartmann takes Legat to a local nursing home to see Lena, revealing that in 1935 she attended an anti-Nazi rally, only to have a Star of David carved in her back and thrown from a window after she was found to be Jewish, resulting in paralysis and an inability to speak. Hartmann reveals he intends to assassinate Hitler much to Legat's dismay. When Legat returns to his hotel, he finds his room has been ransacked by Franz (who had seen Legat meet Hartmann at a local pub and had started tailing him) who attacks him. Legat discovers the document is gone and panics, but he is able to get a discreet message to Hartmann informing him. Meanwhile Chamberlain asks Hitler to sign a document of peace between Britain and Germany, which Hitler does. Chamberlain considers this as a great victory. Hartmann meets with Hitler to deliver the morning news reports but cannot bring himself to shoot him.

As Legat enters the car bound for the airport, typist Joan Menzies (Anjli Mohindra) reveals she is the niece of a British army colonel (assigned to keep a watch out Legat), and that she took possession of the document to prevent Sauer from finding it. Chamberlain returns to Britain a hero and gives his famous Peace for our time speech. Legat returns home to his wife and son, revealing that with the war coming, he plans to quit his job and join the RAF. The Munich Agreement ultimately fails and World War II begins just one year later. Chamberlain resigns in disgrace before dying soon after. The document, however, prompts the British to prepare for and ultimately win the war.