Henry is awoken by the "nuisance" of an Austrian gun battery firing in the distance. He goes to the garage where ambulances are being repaired and chats casually with a mechanic about the gun battery and about the day-to-day operations of fixing machines.
Henry reacts to enemy fire with manly understatement, calling it a "nuisance." At the same time, it is possible to interpret Henry's making light of the war as an effort to escape its horrors.
That afternoon, Rinaldi invites Henry to accompany him to the British hospital to meet Catherine Barkley. Catherine is beautiful, with long blonde hair, and she and Henry begin flirting as soon as they're introduced. At one point, Henry comments on the riding crop Catherine carries. She tells him that it belonged to the man she was engaged to, who was killed in a battle in France. She asks Henry if he has ever loved anyone. He says no. On the walk home, Rinaldi comments that Catherine seems to like Henry more than him.
Catherine has experienced both love and loss, while Henry has not. Before her fiancé died, she had been innocent about what war and love really mean, as Henry is now. Yet Catherine seems to sense something in Henry that makes her trust him as someone she can confide in.