Lt. Frederic Henry was an American ambulance driver in the Italian army in WW1 who meets a nurse by the name of Catherine Barkley and the two fall madly in love with each other. They try to spend every free minute they have together. But that comes to an end when Henry's team is transferred to another base. Henry displays acts of courage and heroism throughout the book. For example when a mortar shell hit Henry’s bunker, he decided to help the injured men inside despite the fact that he was badly injured himself. While reading this book I have learned that no matter how selfless someone is, tragedy can always strike. When Henry's bunker was hit with a mortar he was sent to a hospital in Milan. Many doctors advised Henry to stay in bed for six months and wait for the operation for his knee. He could not stand waiting that kind of time before going back to the front. Luckily for Henry, he found a doctor, Dr. Valentini, who was willing to operate right away on his knee. After being separated for a while Henry and Catherine are reunited after his surgery. Catherine was also transferred to Milan because the hospital was short staffed. During the months of Henrys recovery, Catherine takes care of Henry and their love intensifies as time goes on. The scripted cliches of what a relationship is supposed to be quickly fades into a very sincere and real love for each other.
The Italian government granted Henry a three week convalescence leave before returning to the front. Unwilling to go to the front Henry heavily drinks until he is diagnosed with jaundice. The superintendent of the hospital was extremely angry and revoked the the three week leave from him. Before going back to the army Henry and Catherine declare their undying love for each other when she also she reveals she is pregnant. As Henry arrives to the front he is informed that the Italians are losing ground and manpower to the Germans. The Allied forces are preparing to retreat leaving the Italians with no more reinforcements. As a leader, Henry gathers his team and other ambulance drivers to evacuate the area. They take the back roads of Bainsizza thinking it would be safer and quicker. Along the way the convoy of evacuating men pick up two engineers and two women. Unfortunately driving on the back roads was not the smartest choice and one ambulance in the convoy has gotten stuck in the mud. Henry orders the two engineers to help come up with a way to help the ambulance get unstuck. They refuse and Henry shoots one of them. The remaining engineer helps the ambulance but later it gets stuck again. Everyone abandons the vehicles and continue to a city called Udine on foot. As they are marching one of the drivers has been shot by a frightened Italian guard, another driver has surrendered himself to the Germans, Henry and the remaining men seek refuge in a farmhouse.
Henry and his men rejoin other retreaters, chaos has broken out amongst everyone. Soldiers angered by the Italian defeat are pulling the commanding officers and executing them thinking it was their fault for the defeat. The battle police arrive and pull Henry aside, in a very small window of opportunity Henry escapes and jumps in the river.
After swimming downstream he finds a railroad and sneaks on a cargo train heading back to Milan, where Catherine is still working. Henry gets off the train and manages to find his way to the town of Stresa where he finds Catherine. After talking for a while they agree to run away to Switzerland to be safe. They find a tiny row boat and row all night and settle