Edward, a wealthy nobleman, is long in love with Charlotte, but each is forced to wed someone else. Their first spouses die, however, before many years elapse, and soon afterward Edward and Charlotte are married. With Charlotte’s daughter Luciana placed in a good school, the pair, happily married at last, settle down to an idyllic existence at Edward’s rural castle. They spend their time working at pleasant tasks about the castle and its park, leading together the kind of life for which they long hoped and dreamed.

One day, a letter comes to the happy couple. The Captain, long a friend of Edward, is out of a position. Edward immediately suggests that his friend be invited to the castle, where the Captain can help in improving the grounds and buildings. At first Charlotte withholds her consent, but finally she agrees to her husband’s earnest desire. She reveals that she, too, thinks of inviting someone to the castle, the daughter of a dead friend. Charlotte takes the young woman, Ottilie, as her protégé because of her friendship with the girl’s mother. Ottilie, who is at school with Luciana, is not immediately invited for the visit Charlotte plans.

The Captain arrives shortly, and his presence soon makes marked differences in the household. In order that he and Edward might work together undisturbed and with greater convenience, Edward moves from the wing in which Charlotte’s rooms are located to the wing in which the Captain is placed. Charlotte sees less and less of her husband. One evening, the three read about the elective affinities of chemical elements and speculate on how people are also attracted to one another in different combinations and in varying degrees. The invitation to Ottilie is again discussed. Since Ottilie is not doing well in school, and because Charlotte clearly needs additional companionship, Ottilie is immediately sent for.

When Edward saw Ottilie and was in her company on previous occasions, Ottilie made no impression on him. Seeing her in the same household, however, he soon becomes aware of her attractiveness. It becomes obvious, too, that Ottilie finds Edward attractive. The two fit together strangely well. When they play duets, Ottilie’s mistakes coincide with Edward’s. Gradually, as the two spend more and more time together, Charlotte and the Captain often find themselves together, much to their delight. After some weeks pass, Edward realizes the extent of his influence on Ottilie, all of which make him rejoice. Recognizing the force of his passion, he makes efforts to cause it to grow, as it does steadily and swiftly. Although Charlotte notices the attentions he pays Ottilie, she refuses to become upset by them; since she discovers her own regard for the Captain, she can more easily overlook her husband’s behavior.

One day, while Charlotte and the Captain are out boating, their passion for each other can no longer be concealed. Considering themselves mature people, however, they immediately control their emotions and resolve, after a few kisses, to adhere strictly to the moral path in their conduct. In addition, during one of their periods together, Ottilie and Edward discover their love for each other. More easily swayed and emotionally immature, they welcome the passion and do not try to curb their emotions.

While the relationships among the four are developing, more guests come to the castle. They are a countess and a baron who are spending a vacation as lover and mistress while away from their respective spouses. On the night of their arrival, Edward shows the baron the way to the countess’s rooms, that the lovers might be together. While wishing he could enter Ottilie’s room with the same freedom as the baron enters that of his mistress, Edward finds himself at his wife’s door. He knocks and is admitted. He remains the night with Charlotte, but when he and his wife embrace they do not think of each other, but of Ottilie and the Captain.

The four people are all working on plans for improving the grounds of the castle, with the hope, especially on Edward’s part, that everything might be finished in time for Ottilie’s birthday. On the day of the birthday celebration, Edward makes a public spectacle of himself, proving almost a fool in his ardor for Ottilie. Finally, Charlotte suggests that Ottilie be returned to school or be sent to live with other friends. Edward, angry and frustrated in his love, leaves the castle. When he leaves, he vows he will have nothing more to do with Ottilie, as Charlotte wishes, so long as Ottilie remains. On the same day, the Captain, who receives a position that promotes him to the rank of major, also leaves the castle.

Shortly after Edward’s departure, Charlotte, discovering that she is pregnant as the result of the night her husband spent in her apartments, calls on the services of Herr Mittler, a volunteer marriage counselor. Herr Mittler, however, is unable even to begin a reconciliation with Edward, whose passion for Ottilie conquers him completely. Edward was accustomed all of his life to doing as he pleased and cannot see why he should not have his way in this matter. When war breaks out, he enters the king’s service. He serves gallantly and wins many honors. He believes that if he lives through the war he is fated to have Ottilie.

Meanwhile, Charlotte endures her pregnancy, but she and Ottilie are no longer close to each other, for the younger woman becomes suspicious of Charlotte. For a time life at the castle is enlivened when Luciana arrives for a visit with a large party of her friends. During the entertainment of the visit, Luciana pointedly leaves Ottilie out of the activities arranged for the guests.

Ottilie’s friend during the trying weeks after Edward leaves is a young architect hired to supervise the building of a summerhouse. Although his work is completed, Charlotte keeps him on to redecorate the local church. The young man admires Ottilie very much. A young schoolmaster who taught Ottilie also expresses interest in marrying her, but Ottilie can think only of Edward.

At last a son is born to Charlotte. At the christening Ottilie and Herr Mittler, who stand as sponsors for the baby, are surprised to note how much the infant resembles both Ottilie and the Captain, a resemblance soon noted by others. Charlotte, remembering how she dreamed of the Captain while embracing her husband, guesses that Edward was dreaming at the same time of Ottilie. In a sense the child, named Otto, is a symbol of the parents’ double adultery.

Edward returns to a nearby farm when the war ends. He meets the Captain and makes a proposal to solve everyone’s problems. He suggests that he and Charlotte divorce, so that he can marry Ottilie and Charlotte can marry the Captain. Although the ethics of the plan do not appeal to him, the Captain agrees to take the suggestion to Charlotte. When the Captain sets out for the castle, Edward also visits the grounds in the hope of seeing Ottilie. They meet, and Ottilie is extremely upset, so much so that while returning to the castle alone in a small boat she drops Charlotte’s baby overboard. The child drowns. When the Captain arrives at the castle, Charlotte shows him the little corpse that is a miniature of himself.

Ottilie decides to go away. Edward meets her at an inn and persuades her to return to the castle with him. There the four—Edward, Charlotte, Ottilie, and the Captain—try to resume the happy life they knew before. Ottilie, however, seldom speaks and eats her meals in her rooms. One day she dies suddenly, having starved herself to death. It comes out that Nanny, her little protégé, was persuaded to eat the food intended for Ottilie. Edward also begins a fast. When he dies a short time later, although not as the result of his fasting, he is laid in a tomb beside the woman he loved. In death for one, in life for the other, the two couples are finally united.