(a) How is Bruce, Alceé's manservant, important and what information does Alceé give him that he provides to Clarisse? b) What is the denouement and how do the actions of Clarisse and Calixta influence the outcome "At the 'Cadian Ball"?

In Chopin's short story "At the 'Cadian Ball," Bruce, the manservant of the Laballières, tells Mademoiselle Clarisse that Alceé Laballière has gone to the Cajun (Acadian) ball. He explains that because of the destruction of his rice fields by the storm, as well as the rejection by Mademoiselle Clarisse, Monsieur Laballière said he needs to have a "lit'le fling" in order to forget his misery. Later at the ball, the appearance of Clarisse dramatically changes the lives of the characters. Although Alceé whispers into the ear of the seductive Calixta in his desire and she is responsive, when Clarisse appears, claiming that he must come home because something of "serious import" has happened, Alceé leaves with her, and she tells him that she loves him. After hearing this, Calixta is "like a myth now" to Alceé. Afterwards at the ball, Calixta agrees to marry Bobinôt.
 
(a) When Mlle. Clarisse goes to the moonlight window to say her evening prayers, she notices that Bruce, their "negro servant," stands holding her cousin's horse. Then, she witnesses Alceé come out with two full saddlebags, quickly mount his horse, and depart. In haste, she opens her door and demands of Bruce to know why he has been outside waiting with Alceé's horse saddled, and why her cousin has two saddlebags filled. The servant is hesitant about revealing anything. But, Mlle. Clarisse insists, so Bruce explains that Monsieur Labellière is distraught over losing the rice crop to the terrible storm: "He 'low he come back in couple weeks o' so." Bruce adds that M. Labellière has said, 

"But w'en God A'mighty an a 'oman jines fo'ces agin me, dat's one too many fur me." [When God and a woman join forces against me, that's too much for me.]

This statement alludes to the rejection of Alceé by Clarisse a day or two before the cyclone has struck. At that time he came in directly from the rice field and "panted a volley of hot, blistering love-words in her face," but she refused his advances. So, from the information that Bruce gives her, Mlle. Clarisse realizes that Alceé feels that he needs to run away from his responsibilities and possibly his personal attachments, as well.
(b) Worried that she will lose Alceé to the seductive atmosphere of the 'Cadian ball, Clarisse has her own horse saddled and arrives there; first, she has a servant address Alceé, but he pays no heed to what this man says. Then, Clarisse draws near in the dark as Alceé and Calixta sit together speaking in low and soft tones, "as lovers do." She calls his name.

It was not the negro's voice this time; but one that went through Alceé's body like an electric shock, bringing him to his feet.

Clarisse stands there, dressed in her riding-habit, and for an instant Alceé feels confused, as though waking from a dream. He senses that something "of serious import" has brought Clarisse to this ball in the middle of the night. Therefore, he asks her what her sudden appearance means. She tells him that something has happened at home and he must come at once. Immediately, he becomes anxious about his mother, but she assures him that "nénaine is well, and asleep." Again, she insists that he come with her, and recognizing Calixta, Clarisse politely greets her.
Alceé follows Clarisse without even glancing back at Calixta. But, when Clarisse whispers to him, he turns to say "Good-night, Calixta," and offer his hand; however, Calixta pretends not to see it. Later, Bobinôt finds Calixta alone, and to his delight, Calixta alludes to his many proposals for marriage, and now agrees to marry him: "Well, if you want, yet, I don' care, me." Clearly, she finally accepts Bobinôt because of Alceé's rejection.Then, as Alceé and Clarisse ride homeward, her saddle girth loosens, so she must stop and have it tightened. As Alceé readjusts it for her, he asks Clarisse what is wrong:

"Is it misfortune?""Ah, Dieu sait! [God knows!] It's only something that happen' to me."

Clarisse reveals that when she saw him ride off the previous night, she realized that if he did not return, "I couldn't stan' it,--again." She states that she loves Alceé, and when she declares her love, Alceé "thought the face of the Universe was changed," just as the world has changed for Bobinôt.