It is Christmas-time. It has been 2 months since David has returned from abroad, and he is in a state of oppression with regard Agnes whom he visits frequently. The state of oppression has to do with David’s resignation—resignation that his chance to take Agnes as a wife has long passed, and that he must hitherto settle for being her brother and best friend. Once, he had tried to breach this topic vis-à-vis Agnes only to fail. He’s determined to do it now and forever put to rest the feeling that it could be something more than a friendship.
David’s aunt is skeptical that David’s horse would be in favor of riding to Canterbury today, as it is a bitterly cold, but concedes that if the ride will make David feel better, then he should undertake it.
When David arrives at Canterbury, David finds Agnes has finished teaching for the day, and that her students have departed. They sit down to talk. David asks Agnes if he has ever betrayed her confidence, alarming Agnes. David wonders whether Agnes is keeping a secret from him, and that if she is, she would do well to reveal that secret, as they are the best of friends and practically brother and sister. Who is Agnes’ lover, David asks, and why does she insist in keeping it a secret from David?
At this, Agnes gets up, isolates herself in a corner, and in a state of tears asks David to leave her for now. David stays, however, arguing that he cannot possibly leave Agnes in such a state. David presses on, urging Agnes to share all her confidences, but Agnes, who has regained some of her composure, argues that the topic is particularly sensitive to the extent she must keep it a secret. Agnes tries to leave but David detains her and again goes on at length about their friendship which he values above all else before he tells her about the resolution he had come to. (That he realized that the time when he could have taken Agnes as a wife had passed and that he must now settle for being her friend and brother.) When David mentions this, David sees the truth: That Agnes loves him, not as a brother but as a husband-to-be.
Subsequently, Agnes tells David that she had always loved David as a husband-to-be.
It is around dinner-time the next night when David arrives at his aunt’s house; Agnes has come too. David’s aunt scrutinizes David through her eyeglasses, removes her eyeglasses in despair, and then rubs her nose. She does this repeatedly on account of David who doesn’t betray the fact that he and Agnes are engaged when, after dinner, David steps around to Agnes’s side and embraces her. The secret is out. The news delights David’s aunt to the extent she summons Peggotty and hugs her. Then she hugs Mr. Dick.
Within a fortnight, David marries Agnes in a small, private ceremony where the guests are confined to Traddles and Sophy and Doctor Strong and Mrs. Strong. On their way to their honeymoon, Agnes tells David Dora’s last wish, something that Dora had shared with Agnes and Agnes alone. Dora’s last wish was that when she died she wanted Agnes to take David as her husband.