Before a special evening at the Royal Yacht Club, Ludvig von Battwyhl, Håkan Westergren engages in a quiet exchange with Andersson, Axel Högel the club valet. The phone rings with a caller stating that Louis Brenner, Kotti Chave will not arrive. Katja von Battwyhl, Birgit Tengroth and Sussi Brenner, Tutta Rolf share the disappointment of Louis’s absence and join Julia Balzar, Ingrid Bergman, a wealthy Swedish actress married to Kurt Balzar, Georg Rydeberg, a Swedish industrialist. At a nearby casino, Louis is a compulsive gambler who has lost over 50,000 kronor. All three couples plan to vacation at the Åre ski resort. Brenner is later notified that his wife Sussi has taken ill. He writes a cheque to his opponent promising to cover his losses.
When Louis arrives, he is angered that his wife lied. He tells Julia about his gambling debts, but declines her assistance. Before leaving the Balzars’ residence, Louis apologizes to Sussi, and they depart. Alone, Kurt, who is jealous of Julia’s affections toward Louis, angrily tells Julia he will not cover Louis’s gambling debt. The next day, Julia learns from Ludvig that her husband’s company shares are in decline at the stock market. She calls their bank to prevent 200 shares from being sold. Ludvig writes a cheque to cover their losses, which Julia gives Sussi to pay off Louis’s debt.
Nearby the ski resort, Dr. Jonson treats an infant girl, ill with a fever. At the hotel, Sussi asks Ludvig about who wrote the cheque and deduces it was Julia. She catches Louis eavesdropping, insults him, and locks herself in her room. With their marriage in trouble, Ludvig advises Louis to have another child. Louis then asks Ludvig if he wrote the cheque, but Ludvig denies it; Louis suspects Kurt wrote it. Julia arrives at the resort.
During a blizzard, Sussi wanders outside and is picked up by a couple in their vehicle. She is driven back to the resort but is unable to walk on her legs. She is placed under the attentive care of Karin, a nurse, Millan Bolander. Mary Jonston, a wealthy American who fancies herself a psychoanalyst, arrives, and diagnoses Sussi as having severe psychological distress. At a medical clinic, Sussi has not slept for several hours but makes amends with Louis. She further forbids Julia from visiting the clinic. There, Mary flirts with Dr. Jonson, betting with him to successfully cure Sussi’s paralysis in 12 hours, and if he wins, she will donate 10 free stays at his clinic; if she wins, Jonson will have to marry her.
However, Julia arrives at the clinic and meets with Louis in a hallway. Sussi overhears their conversation, and tries to walk but falls down. Julia comforts Sussi, and Sussi tears up as she falls asleep. During dinner, Mary feels she has won since 18 hours have passed and Sussi is not yet cured. She gathers all three couples to psychoanalyze Sussi’s condition. She reveals that Julia wrote the cheque using Ludvig’s money. Ludwig agreed because he was in love with Sussi. Sussi attempted to freeze herself to death, but she tearfully denies it. Sussi rises from her chair and walks again. The three couples settle their differences, and Sussi thanks Dr. Jonson.
Back in his office, Jonson corrects Mary, stating it was actually Katja’s money that was used to cover Louis’s debt. Jonson calls off the wager and prepares to leave the resort, which angers Mary. Back in their hotel room, Julia and Kurt reconcile. Mary knocks on their door, telling Julia about Dr. Jonson’s betrayal toward her. Julia reassures Mary that Jonson loves her. Before Jonson leaves, Mary professes her love to him. The two kiss.
