Frederic drops off the train in Milan and goes to a wine shop for coffee and bread. The proprietor offers him some grappa and asks about the front. The proprietor immediately gleans that Frederic is in trouble and offers to help but Frederic insists he needs no help and leaves the shop. He takes a cab to hospital and calls on the porter and his wife who are happy to see him. He learns that Catherine has gone to Stresa. He takes another cab to the house of his friend Simmons who is studying singing. He finds Simmons still sleepy and in bed but very friendly. He learns that if he goes to Switzerland he will be officially interned but allowed to go anywhere he wants. When Simmons learns that Frederic must first go to Stesa he says that all he will need to do is row across the lake to Switzerland. Simmons gives Frederic some of his clothes and insists he stay for breakfast. Simmons is upset because although he can sing, he is not being received well in Italy.
In civilian clothes for the first time in a long time, Frederic takes the train to Stesa. On the way, soldiers give him scornful glances but since he has made a "separate peace" he is not bothered. The season is over in Stresa and there are not many people about. He takes a carriage to one of the larger hotels that stay open all year and he takes a good room with a view of the lake. He tells the staff that he is expecting his wife. He goes to the bar for a martini and the barman, whom he knows, offers to find out where the two English nurses are staying. He learns that they are staying at a small hotel near the station and after some more martinis and sandwiches Frederic goes to their hotel. He finds Catherine and Miss Ferguson in the dining room and Fergy gives him a hard time and is suspicious of his civilian clothes. Nevertheless, she intuits correctly that the two plan to "sneak off". Ferguson becomes emotional and Catherine, obviously overjoyed at Frederic's return, tries to comfort her.
Catherine joins Frederic in the larger hotel and that night, with the rain falling, he realizes that with Catherine he does not feel lonely or afraid. In the morning they have breakfast in bed and upon questioning, Frederic admits that if he is discovered he will most likely be shot. Catherine insists that they leave the country and he suggests Switzerland. When he says that he feels like a deserter she protests: "It's only the Italian army" and he laughs. They agree to leave at the soonest opportunity.
Catherine goes to see Ferguson and Frederic goes to the bar. The barman tells him that a mutual acquaintance, Count Greffi, a ninety-four year old former ambassador for both Italy and Austria, wishes to play billiards during his stay. Frederic and the barman go out fishing in the barman's small boat. Though they have no luck with the fish, they stop at an island for a drink. On the way back Frederic feels a strike in the trolling line but does not hook the fish. The barman offers the boat anytime Frederic wants to use it. Catherine and Frederic have lunch with Ferguson who is enamored of the grand hotel. Catherine privately lets on to Frederic that Ferguson is jealous of their love. After lunch Frederic and Catherine lie down in the room together. A servant comes to request that Frederic play billiards with Count Greffi that evening and he agrees though he is loath to leave Catherine. The count is very cordial and refined and they play a friendly game of billiards for stakes. Halfway through, they partake of some champagne. The count wins the game even after granting Frederic a handicap of eighteen points. After the game they drink a second bottle of champagne and the count expresses his regret that as he has grown older he has not become more devout. He reassures Frederic that love for a woman is a form of devotion. Frederic says, "It was a great pleasure" at their parting.
That night there is a storm. The barman, whose name is Emilio, comes to warn Frederic that in the morning he is to be arrested. Emilio advises Frederic to use his boat to flee to Switzerland. Frederic assents. Catherine pragmatically agrees to the journey. On the way out the porter insists that they take his big umbrella. The barman meets them at the boat with their bags and refuses immediate payment for the boat because they might need the money in Switzerland. He gives them sandwiches, brandy and wine and accepts fifty lire for the food and beverages. The barman tells Frederic how to row to Switzerland. It is eleven o'clock and the barman estimates that if they row all night they should cover the thirty-five kilometers and arrive in Swiss waters by seven in the morning.
Frederic rows the small boat through the rough waters all night. He and Catherine mark their progress by the lights of the towns they pass. Frederic's hands grow sore from blisters. At Catherine's suggestion he uses the big umbrella as a sail but the wind catches it and turns it wrong side out. Catherine laughs at the sight of Frederic struggling with the upturned umbrella. After drinking some of the brandy Frederic rows some more. There is a full moon and for fear of being spotted by Italian border patrol officers on the lake they stay far out in the lake. Catherine rows while Frederic takes a break and she observes that if an oar hit her stomach life might be easier. He resumes duty at the oars.
At daylight they see a patrol boat and a little later Frederic says they might be in Switzerland. Catherine expresses her desire for a big breakfast with rolls and butter and jam. They land in a small town they believe to be Brissago. They leave the boat at the shore and have breakfast in a cafe. Catherine is disappointed that they don't have rolls but they are both thrilled to be in Switzerland. After breakfast they are arrested but their American and British passports, their money and Frederic's excuse that he is a sportsman looking for winter sport and that Catherine, whom he calls his cousin, is studying art is sufficient to clear them of suspicion. They are granted provisional visas and two of the officials engage in a comical argument over whether the couple would have better winter sport in Montreux or Locarno and they debate the differences between lugeing and tobogganing. Catherine desires to go to Monetreux, however, and that city wins out. Catherine and Frederic are slightly delirious and groggy but very happy when they reach the hotel.
In a wonderfully deadpan moment, Frederic survives near execution and drowning followed by a torturous train ride only to check into a nice hotel and find Catherine at lunch with Miss Ferguson who becomes emotional at the thought that Catherine will leave her all alone in Stresa. Fergy's questions about their intentions, far from driving them further apart, help them to reaffirm their mutual understanding and love. Frederic's failure to see that Fergy's emotions are rooted in jealousy reveal that he has a few things more to learn about the inner life of women.
Frederic's dialogue with Count Greffi in a sense completes the thoughts previously espoused by the priest and brings to Frederic's attention the true scope of his love for Catherine. He realizes that she has become his religion and that which he desires to serve. During this brief interlude in Stresa, Frederic is happy to simply be with Catherine and though he could be shot if he is discovered he doesn't take any concrete steps to secure his safety. This is due in part to complacency and in part out of consideration for Catherine's well being. The barman's warning presses the issue for them and they resolve to flee immediately. Frederic and Catherine's ordeal crossing the lake mirrors Frederic's earlier escape from the executioners but this journey they take together. It is the final separation from their old life in Italy and its associations with the war to a new one in Switzerland that has as its foundation only their devotion to each other.