In 1928 Paris, a group of exiled White Russians claim to have found the living daughter of the Tsar, presumed executed in 1918.

In Paris in 1928, a downtrodden woman wandering the streets is approached by Gen. Bounine, a Russian exile who once served as an officer in the Russian Imperial Army, and who now runs a Paris nightclub. When asked by Bounine if she is the Grand Duchess Anastasia, the woman claims that her name is Anna Korov and adds that she has just been released from an asylum. Anna dodges her way through the streets to the banks of the Seine, and is about to jump when she is saved by Bounine. Meanwhile, in their cellar headquarters, Chernov and Petrovin, Bounine's partners in a business enterprise to produce the grand duchess and thus claim her ten million pound inheritance, worry that they will be unable to meet the deadline that their stockholders have given them. Just then, Bounine arrives with Anna, and although he discounts her authenticity, he is confident that he can mold her into the image of the grand duchess. Anna, haggard and suffering from bouts of amnesia, bears scars on her palms and forehead, similar to those inflicted on Anastasia during the massacre of her family at the hands of the revolutionaries. Anna, weak and susceptible, succumbs to Bounine's promises to help her find herself and agrees to become his Anastasia. Daily, Bounine tutors her on Romanov family history and schools her on royal comportment. With just three days left until the deadline, Bounine arranges for Anna to meet a few of the more gullible stockholders. When Anna is introduced to the Czarina's former lady-in-waiting, the woman breaks down in tears of disbelief when Anna addresses her by her nickname, a name known only to the royal family. Anna's next test occurs at a reception for Russian exiles. There, Bounine reminds the crowd that it is their duty to restore Anastasia to the living and asks them to sign a document vouching for her authenticity. The Czar's chamberlain calls Anna a great illusionist until she rebukes him for smoking in her presence, just as Anastasia once did. When only eighteen of the fifty-one present sign the document, however, Bounine decides he must introduce Anna to the Dowager Empress, Anastasia's grandmother, who resides in Copenhagen. Anna, now assured that she is the grand duchess, scorns her doubters and decides to go off on her own. Bounine convinces her to accompany him to Copenhagen, however, and the two travel to Denmark, where Anna, traveling under the name A. Anderson, is granted a fourteen-day visa. When the empress refuses to meet with Anna, Bounine arranges a rendezvous with Baroness Elena von Livenbaum, her lady-in-waiting. The baroness, infatuated with the dashing Bounine, tells him that the empress will be at the Royal Theater on Thursday. That Thursday night, Bounine escorts Anna to the theater and there introduces her to Prince Paul, the empress' nephew and Anastasia's betrothed. As Paul and Anna converse in the lobby, Bounine gains admittance to the empress' box. After coldly informing Bounine that she is weary of all her "spectral grandchildren," the crusty empress refuses to see Anna and deems Bounine's interest purely monetary. After he leaves, the empress intently studies Anna through her binoculars. Paul begins to squire Anna around town, and one night at the Tivoli Club, Anna, tipsy from champagne, giggles and kisses Paul. Bounine, jealous, intrudes and sends Anna home to bed. Paul, a womanizing fortune hunter, presses his aunt to meet Anna, and one day, the empress unexpectedly appears in her hotel room. The empress, imperious and unyielding, excoriates Anna for manipulating the Romanov legacy for financial gain. When Anna recalls a quarrel her grandmother and father once had over a necklace, the intimate memory distresses the empress and she offers to pay Anna to end her charade. The lonely empress secretly longs to reunite with her lost granddaughter, so when Anna coughs nervously from fright, as Anastasia once did, the empress embraces her as the grand duchess. Weeks later, Paul, the empress and Anna return to Paris amid rumors of Paul and Anna's impending engagement. When Anna is introduced to the press, Viados, a reporter, claims that she is really Anna Korov and that her wounds were incurred during a train explosion. Afterward, Bounine and Anna see each other for the first time since Copenhagen, and he accuses her of being seduced by the wealth and status of the grand duchess. On the night that the empress is to present Anna as her heir, Bounine informs the empress that he plans to leave before the presentation. Sensing that Bounine is in love with Anna, the empress asks him to wait in the green room. The empress then asks Anna if she really wants to marry Paul. Perceiving that Anna is in love with Bounine, she sends her to the green room where Bounine waits. As Chernov and the others prepare to present Anna, they discover that she has disappeared with Bounine. The empress then grandly proclaims that the play is over and everyone should go home.