In the morning, Miss Gage tells Henry that she discovered his secret wine. He worries that she will turn him in, but is surprised when she says that she wishes he had told her so that they could have shared a drink. Then she tells him Catherine Barkley has arrived, and that she doesn't like her. Henry promises her that she will eventually like her.
Miss Gage dislikes Catherine because Miss Gage is also attracted to Henry. Just like the ambulance drivers and Henry himself, Miss Gage is willing to bend army rules. Anyone unwilling to bend rules is painted as a kind of strict military zealot.
At Henry's request, a barber comes to give Henry a shave. Henry tries to make conversation with the man, but the barber angrily threatens Henry with the razor. Afterward, the amused porter tells Henry that the barber thought he was an Austrian officer.
In wartime, there can be a razor-thin line between comical events and tragic misunderstandings.
A bit later, Catherine appears in Henry's room. He knows that he is in love with her the moment he sees her, and pulls her onto his hospital bed as soon as she closes the door. They make love for the first time. Afterward, Catherine warns him that they will have to be more careful in the future. She leaves, promising to return soon. Henry considers that he hadn't wanted to fall in love, but he has anyway.
Both Henry and Catherine have been traumatized by the war and need the comfort that the other can provide. Their love is founded on their ability to help each other "escape" from the war. That they have to keep their affair secret only adds to the intensity of their privacy.