The story opens with a framing device set in post-Second World War Britain. When a young man comes to aged Anton Marek (Albert Lieven) for romantic advice, Marek tells him a story from his own past, which leads to a flashback.
In the days leading up to the First World War, Lieutenant Marek is assigned to an Austro-Hungarian cavalry regiment stationed in a small town. There he meets Baroness Edith de Kekesfalva (Lilli Palmer), a young woman who is a paraplegic as the result of a horse riding accident. Noticing how the young man has cheered up his depressed daughter, Baron Emil de Kekesfalva (Ernest Thesiger) asks him to spend time with her. Marek finds her company pleasant enough and agrees.
The baron has consulted many renowned doctors in vain; none hold out any hope for his daughter's recovery. Finally, in desperation, he has turned to hardworking, dedicated Dr. Albert Condor (Cedric Hardwicke), who at least refuses to give up. Condor notices a great improvement in Edith's attitude, which he accurately ascribes to her falling in love with Marek. Marek remains unaware of Edith's feelings for him.
One day, Marek tells the family about a promising treatment in Switzerland, despite Condor's warning to wait until he has had a chance to investigate. Condor later informs him that it cannot help Edith, but by then the damage is done. With the hope of being able to walk again unassisted, Edith reveals her love for Marek. Guilt-ridden, the young man pretends to love her and agrees to marry her after she is cured.
However, when rumors of the engagement leak out, Marek angrily denies them to his questioning, disapproving fellow officers. When he is confronted by his commanding officer, Marek admits the truth. To minimize the scandal, his commander immediately arranges his transfer to another unit far away.
Marek goes to see Condor before he leaves, but the doctor is away. Instead, Condor's blind wife Klara (Gladys Cooper) speaks with him. She gets him to recognize that he may love Edith after all. He tries to telephone Edith, but the lines are barred from civilian use because of the assassination of Archduke Franz Ferdinand that same day. Marek must take the train to report for duty with his new unit, but Klara assures him she will see Edith and clear things up.
When Klara visits Edith, she finds her alone on the rooftop terrace of her family's mountainside mansion. Edith has heard about Marek's public denial of their engagement and no longer trusts anyone. With Klara powerless to stop her, she wheels herself to the edge and flings herself over to her death.