The Mysterious Lady is a 1928 film directed by Fred Niblo, starring Greta Garbo.
Vienna, some time before the outbreak of World War I. Army Captain Karl von Raden (Conrad Nagel) goes to the opera one night with his friend Max Heinrich. The show is sold out, but Karl manages to snag one ticket when it's returned. Said ticket gets him a seat in a box...next to a luscious beauty, Tania Fedorova (Garbo).
After the show Tania admits that she forgot to bring money for a cab. Karl seizes on this chance to escort her home. A nightcap follows, which is followed by sex. The whirlwind romance is soon ended when Tania, without explaining why, says that she must go back home to Russian Poland. Soon after her departure Karl is charged with delivering secret plans to Berlin. Tania meets him on the train and begs forgiveness. He angrily rejects her, she leaves brokenhearted—and Karl discovers that the plans have been stolen.
Compare Mata Hari, a talking Garbo film that had a rather similar plot.
- Chiaroscuro: An artfully shot scene when the power goes out at Tania's house and she starts lighting candles—kissing with Karl ensues.
- Dances and Balls: The climax occurs at an elaborate ball thrown in honor of Tania's birthday.
- Erotic Eating: A scene where Tania and Karl are canoodling in the park, feeding each other snacks.
- High-Class Glass: Max Heinrich, Karl's friend in the army, sports one. This is an early hint that he's the bad guy.
- High-Heel–Face Turn: Tania's love for Karl, and her desire to keep him out of prison, lead to her stealing the plans back, revealing Max Heinrich as the traitor, shooting Boris, and escaping back to Austria with Karl.
- Holding Both Sides of the Conversation: Tania has just shot Boris dead, Boris collapsing into a chair. The chair happens to be positioned with its back to the door. When Boris's goons come in, Tania, with Boris's arm wrapped around her waist, tells the goons that Boris wants Karl sent in alone. After Karl is sent in, he and Tania escape via the hidden passage.
- Honey Pot: It turns out that Tania is this, seducing Karl because she's a Russian spy.
- Insignia Rip-Off Ritual: The "degradation" ceremony, something done in Real Life in European armies prior to World War I, in which a disgraced officer has his sword broken and all his medals stripped. Done to Karl when he's cashiered and before he's sent to prison.
- MacGuffin: Plans for Austrian border fortifications, stolen by Tania.
- Meet Cute: Seems like this, as Karl snags the last ticket to an opera and is surprised to find a gorgeous woman in the box. Later subverted when he finds out that the meeting was deliberately arranged.
- The Mole: Turns out that Max Heinrich, Karl's fellow officer and friend, is spying for the Russians.
- Resignations Not Accepted: Tania expresses dissatisfaction with a life of espionage. Her boss and would-be lover, Boris, tells her that "When one takes the oath to serve the Czar as a spy—the only release is—death."
- Spy Fiction: Big-time martini flavored, with officers in fancy dress uniform, a beautiful Honey Pot, mansions, parties, secret passageways...
- That Russian Squat Dance: Performed, presumably by peasant entertainers, at the fancy ball thrown for Tania.