Not knowing her illness is terminal, concert pianist Karen Duncan checks into a Switzerland sanatorium under the care of Dr. Tony Stanton, whose stern manner Karen does not like. One day she and another patient, Celestine Miller, enjoy a day away from the clinic and a night on the town, despite their doctor's advice.
Auto racer Paul Clermont is introduced to Karen and invites her to Monte Carlo. Although she is attracted to her doctor, Tony's seeming lack of interest in anything but her health causes Karen to accept Paul's invitation. She gambles, smokes and drinks, then returns to the sanatorium to discover that Celestine has died.
Panic-stricken, Karen's first impulse is to follow her doctor's orders to refrain from exerting herself. She disobeys, going away with Paul again and endangering her well-being. Only at the last possible minute does she return to Tony's side, where he proposes marriage to her and watches carefully as their future together hangs by a thread.