Enredo

Vienna in 1906: Frantz Lobheimer has just broken off the discrete love affair he was having with the baroness Eggersdorf, now that he's discovered true love with the young and tender Christine.

Vienna, 1906. A passionate love story develops between Franz Lobheiner (Alain Delon) and the young Christine (Romy Schneider). Lobheiner is, however, currently seeing the married Baroness von Eggersdorf. Upon learning of his wife's infidelity, the Baron von Eggersdorf provokes a duel with Lobheiner. But the former is no longer a real threat to the Baron. Lobheiner is now passionately in love with Christine. How will this love quartet end?—GMeleJr

1906, Vienna. Franz Lobheiner is a Second Lieutenant with the Austrian Army, a position that includes the "expectation" to attend high society functions, a ball where he met and subsequently began an affair with married Baroness Helena Eggersdorf which has thus far lasted one year. But with she needing to sneak away and double and triple check to ensure she has not been followed in their liaisons at his apartment in those infrequent times when she is able, she having a key to let herself in, Franz is beginning to tire of the affair. At the same time, he begins to see Christine Weiring, the innocent daughter of the opera's cellist, solely as a fourth required for double dates between his fellow lieutenant Theo Kaiser and Theo's girlfriend, Christine's cousin Mitzie Schlager. What starts out purely as an awkward obligation for both Christine and Franz turns into the purest of love for both. While Christine already being unofficially engaged to struggling composer Joseph Binder causes a minor inconvenience, it is Franz's affair with the Baroness that causes the major obstacle to a Christine/Franz happy ending in the Baroness not giving up Franz without a fight as she thought that their love was a forever kind, and the Baron not taking her having an affair, if he were ever to discover such, lying down in its betrayal solely against such an important person as himself.—Huggo

In 1906, in Vienna, Lt. Franz Lobheiner and Lt. Theo Kaiser are womanizers best friends and together with their others fellow military officers, they bet who will not seduce women in their leisure time. Franz has a love affair with Baroness Lena Eggersdorf (Micheline Presle), who has the key of his apartment for their encounters. Meanwhile, the naive and inexperienced Christine Weiring goes to the ball with her friends Mitzi Schlager and Joseph Binder, who has a crush on her. Mitzi dances with Theo and Franz talks to Christine, and they schedule a picnic on Sunday. Soon Franz and Christine fall in love with each other, and he looks for Baroness Eggersdorf to end their affair and propose Christine. However, the suspicious Baron Eggersdorf finds Lena's key in her desktop and challenges Franz to a duel, with tragic consequences.—Claudio Carvalho, Rio de Janeiro, Brazil