Martin's relations with Leora seem calm and serene after his more turbulent connection with Madeline. When Digamma Pi is giving a dance, he and Leora shop together for his clothes, finally deciding on dinner jacket and black waistcoat. When they arrive at the ball, however, many of the men wear white waistcoats and even white gloves. At first, Leora has no dancing partners, but after Fatty Pfaff breaks the ice by asking her to dance, she has partners galore. Martin stands and watches her jealously, refusing to ask other girls to dance. She notices his attitude and tells him how much she enjoys dancing and her "dandy partners," promising that she is absolutely his and forbidding him ever to be jealous again. From now on, he is her slave.
Clif Clawson, too poor to attend the ball, meets Martin and Leora afterwards at the door of the Imperial Cafeteria. Clif is favorably impressed by Leora even though she seems to look through his boasting. When Martin is snubbed by Angus Duer, he feels that the insult is directed at Leora. Next day, however, Duer apologizes for his conduct, saying that he had had a headache the evening before; he offers to share four tickets for As It Listeth, a play with a New York cast, if Leora will bring one of her friends and make a foursome. Leora invites a probationer nurse, Nelly Byers.
Things happen fast after the play, which all four enjoy on different intellectual levels. After Nelly Byers goes home by trolley car in order to be in the hospital by a quarter after eleven, the other three linger over beer and Swiss cheese sandwiches. Angus addresses himself to Leora in a way that makes Martin jealous. Arriving at the hospital after hours, Leora is hoisted through a window by the two men. Martin follows to kiss her goodnight, while Angus falls asleep on the stone steps. The night watchman accosts Martin on leaving, and a scuffle ensues, in which Martin barely prevents Angus from stabbing the watchman with a pen knife. The two young men escape through an alley and board the trolley. Next morning, Duer is clear-eyed as usual and rebukes Martin for being "stewed" the night before.
This important chapter advances the story of the romance between Martin and Leora, at the same time throwing new light on the deep-seated characteristics of Angus Duer. Contrast in the two probationary nurses is obvious, Nelly being punctilious about keeping hospital hours, and Leora being careless. This disregard of convention makes Leora all the more alluring to Martin. Again he is made jealous by Duer's attentions to Leora, conferred in rather condescending style. The suave, city-bred Duer shows a surprising murderous streak in his nature, however, when he loses entire control of himself and tries to kill the night watchman.
Suspense is built up from the beginning of the chapter to its lively end, and more action and less detail are included than in much of Lewis' writing. The subject matter is also less technical than usual, there being only a few references to medicine and research. Social affairs, such as the ball and the play, are used as background, reflecting life of the times. Even "white mule" is mentioned casually.