Schtonk!

Knobel forges what he claims are Hitler's diaries and a portrait of Eva Braun. He sells these items to Karl Lenz, a factory owner eager to impress his guests. The successful sale marks the start of a growing forgery operation built on false historical relics.

Lenz invites guests to a birthday party for the Führer and proudly displays the forged diary. The attendees include sleazy journalist Hermann Willié, whose interest in the diary quickly becomes personal obsession. The spectacle shows how the fake artifacts fuel gossip and appetite for more.

Willié's fixation on the diary grows, pushing him toward collecting more Nazi memorabilia. He begins to broaden his ambitions beyond journalism, including the purchase of Göring's old yacht Carin II. His obsession foreshadows the sensational lengths the story will go.

Knobel meets Martha and she becomes his lover, while he is still married to Biggi. Martha inspires the diary version of Eva Braun, linking his forgeries to his own life. The personal entanglements deepen the pressure behind the fake project.

Word of the diaries creates a wave of nostalgia and pseudo-Nazi prestige among the upper class. Former Nazi officials start flaunting their old ranks, such as Obergruppenführer, buoyed by the belief that the diaries are genuine. The social atmosphere becomes receptive to more forgeries and sensational claims.

Willié's obsession leads him to a high-profile liaison with Freya von Hepp, Göring's fictional granddaughter. He also continues to chase more memorabilia and status, further entwining his fate with Knobel's forgeries. The affair amplifies the danger of exposure.

One forged volume bears a monogram 'FH' instead of 'AH,' a discrepancy the journalists try to explain away. They invent alternate facts, such as the term 'Führerhauptquartier' replacing Adolf Hitler, to rationalize the inconsistency. The credibility of the diaries hinges on clever justifications.

Knobel uses a forensic graphoanalysis technique to fend off accusations of forgery. He attempts to steer the test in his favor, exploiting the analysts' expectations. The move buys him time but intensifies the risk of a later discovery.

With the public's appetite for the diaries rising, Knobel faces growing pressure to supply the remaining volumes. He becomes trapped by fear that every new page will reveal the deceit. The tension builds toward an eventual breakdown.

The constant fear and his mounting identification with the person he writes about push Knobel to the brink. He begins to lose grip on reality as the forgery scheme threatens to unravel. The collapse is imminent, signaling a turning point in the story.

Biggi and Martha take charge of the situation, forcing Knobel to pull himself out of the forgery business. They manage to steer him away just as the operation risks imploding. The trio's shift marks the end of the extortionate scheme.

As the forgeries become exposed to the world, the Nazi-enthusiasts' fever dies down, collapsing in varying degrees according to belief. The world moves on, with few lasting consequences for those involved. The film ends with a cautionary note about counterfeit history.