Berlin, Nazi Germany, late 1938: Louise von Hollendorf [Gudrun Landgrebe] visits her former college literature professor to recount the events that have shaped her life, with much of the tale unfolding in flashback and interspersed narration addressed to the Professor [William Berger].
Several months earlier, Louise is married to Heinz von Hollendorf [Kevin McNally], a senior diplomat at the Ministry of Foreign Affairs. His long hours keep him away, leaving her feeling lonely, so she signs up for drawing lessons at the Institute of Fine Arts. There she meets Mitsuko Matsugae [Mio Takaki], the young daughter of the Japanese ambassador, and asks her to model for her sketches. Rumors float around the institute that the two women are lovers. Rather than driving them apart, the whispers draw Louise and Mitsuko closer, and a passionate relationship blossoms between them. As Louise tells the Professor, > One moment we were laughing, the next, we were making love
Their romance begins at Louise’s house and later moves to Mitsuko’s residence on the embassy grounds. Over time Louise finds herself falling deeply for Mitsuko. But Heinz grows suspicious, confronting Louise about infidelity; she denies everything even when the evidence seems clear.
The drama deepens when Louise learns that Mitsuko has also had an affair with Joseph Benno [Andrea Prodan], their half-Italian drawing instructor. Louise discovers Mitsuko and Joseph’s plan to marry and that the pair had spread rumors about Louise and Mitsuko to divert attention from their own mixed romance. Disgusted, Louise withdraws from Mitsuko and returns to Heinz, who is upset yet eventually forgives her.
Meanwhile, the Nazi regime moves against dissidents under the cover of a morality campaign. Wolf von Hollendorf [Hanns Zischler], Heinz’s cousin and a high-ranking Gestapo officer, pushes the couple into a trap designed to reveal Werner von Heiden [Massimo Girotti], a general whose own homosexuality is exposed. At the von Hollendorfs’ invitation, Wolf brings von Heiden and his young pianist lover to the house, then reveals the affair, wrecking von Heiden’s career and forcing him to flee Germany.
A month later, Mitsuko reappears, falsely claiming illness and pregnancy. Louise remains skeptical, but the affair is rekindled with even greater intensity. Joseph Benno, still entangled with Mitsuko, agrees not to interfere if Louise helps them marry. Benno uses this arrangement to blackmail Heinz, and with Wolf’s help, Benno is deported back to Italy.
Heinz becomes determined to separate the three and, to avert a scandal, the lovers plan a desperate ruse to scare him into accepting their relationship. Mitsuko seduces Heinz in a ménage à trois, and at a dinner she drugs the von Hollendorfs to prevent them from having sex, using the ruse to inflame jealousy between Louise and Heinz. Their self-destructive triangle becomes a public embarrassment when Benno’s account is published in a Berlin newspaper, and Heinz is forced to resign as Wolf temporarily blocks their passports.
The trio hides in a seedy hotel, debating their options. Rather than splitting up, they drink poison prepared by Mitsuko as part of a ritual, and lie together in the bed. When Louise awakens, she finds that both Heinz and Mitsuko are dead, realizing she was given a sedative by Mitsuko instead of poison.
At first Louise fears betrayal, but the Professor offers a different reading: Mitsuko may have acted out of loyalty, aiming to spare Louise’s life. The Professor’s final manuscript is entrusted to Louise as he is arrested by the Gestapo, leaving her alone to decide how to carry on with her life.
