The next morning Lady Audley feels better; she is not clear about what will happen to her, but relieved that she no longer has to keep secrets. Dr. Mosgrave arrives at Audley Court. Robert tells him the story Lady Audley has revealed, but does not give any information about George’s disappearance or the fire at the inn. He wants to know if she is in fact insane, and therefore not responsible for her actions. Mosgrave says he will examine her, but does not believe that she is insane, because she has acted in calculated ways to benefit herself. Robert admits to the disappearance of George; Mosgrave says he needs to have all the information if he is to help. Robert tells the rest of the story. Mosgrave briefly consults with Lady Audley and then returns to give Robert his diagnosis: she is not mad, but rather influenced by heredity. He pronounces her dangerous. He also tells Robert, however, that Lady Audley could not be found guilty of murder, since firstly George’s death cannot even be proven, and secondly there is no evidence against her beyond motive. Robert’s biggest concern is avoiding a public scandal. Dr. Mosgrave writes to Monsieur Val, who runs an institution for the mentally ill in Belgium. Dr. Mosgrave recommends placing Lady Audley in this institution, since he believes she could commit violent acts.
Robert orders Lady Audley to begin preparing for a journey, making it clear that she is unlikely to return. Together, they travel rapidly to Belgium. There, Robert completes all official requirements and takes Lucy to the institution, which is relatively comfortable, and not obviously a madhouse, although Lucy recognizes it as such. Monsieur Val is introduced to Lucy as Mrs. Taylor; she is told that Lucy must be kept very comfortably. Lady Audley expresses her rage at finding herself in such a place, and tells Robert that George Talboys’ body can be found at the bottom of the old well at Audley Court. On September 7th, he had approached her alone on the grounds. She had hoped to bribe him to conceal her identity, but he was too outraged and hurt to take her money. He threatened to reveal her identity by bringing witnesses; in rage and desperation, she pulled a loose part from the wooden structure he was leaning on, sending him falling into the well. She tells Robert that she can make this confession now because she knows he would never risk shaming his uncle by involving her in a criminal trial. Robert leaves in horror and shock.
Robert is now at a loss because retrieving George’s body will invariably lead to a legal investigation and reveal Lady Audley’s crime. Back in England, he learns that Alicia and Sir Michael have set off for a trip in Germany, and he receives a letter from Clara, asking him to come and see Luke Marks, who is dying of his injuries from the fire. Robert travels to Audley and with Mr. Dawson goes to the house where Luke is being nursed. When he arrives, Phoebe insists on speaking to him alone first. Phoebe tells him that she doesn’t think Luke remembers anything about Lady Audley’s visit the night of the fire, and asks Robert not to bring it up. Robert then speaks with Luke alone, and Luke brings up the topic of George in conversation. Robert assumes that Luke is going to tell him what he has already discovered about Lady Audley’s involvement in his death and tells him there is no need to recount the story again.
However, Luke continues to express a need to get a secret off of his chest. He asks his mother to recall an evening in the autumn where Luke had brought to her an injured man, covered in wet and muck, clearly in shock after some trauma. Luke then gives Robert two pieces of paper. Both are from George: one is for Robert, saying that he is leaving England forever, and the other is addressed to Helen, forgiving her and promising never to pursue her. George realizes that his friend survived the fall into the well. Luke explains: on September 7th, he had stopped by the grounds of Audley Court because he sometimes met Helen there. He found George lying injured and took him to his mother’s cottage for a change of clothes. George insisted that no one but Luke and Mrs. Marks find out about his situation. As soon as he could walk, he insisted on going to another town, where a doctor helped him. George wrote the two letters and told Luke to deliver them, and then left for Liverpool. By this time, Robert had left and Luke did not know how to contact him, so he could not deliver that letter. He met up with Phoebe, planning to arrange a meeting to deliver the other letter to Lady Audley. Phoebe, however, confided that, from where she had been sitting, she saw what had taken place between Lucy and George, and was now aware of how much power Lady Audley had over her. Luke realized it was in his best interest not to tell Lady Audley that George was alive, and it would be better to blackmail her instead.
Luke dies a short time later, and Robert writes to Lady Audley to tell her that George survived and she is not guilty of murder after all.
Robert is able to tell Clara that George is alive and in Australia. She relays this news to her father, who admits that he is relieved and thanks Robert for all he has done. Robert has by this time become aware that he is in love with Clara, and he proposes. She agrees to marry him, and they plan to sail Australia together to look for George. However, when Robert goes to London to make arrangements, he finds George waiting for him. George explains that he had been able to climb out of the well by relying on some jagged rocks, and had then been assisted by Luke Marks. After leaving Audley, George had actually sailed to New York and eventually returned because he was lonely and missed Robert.
Two years later, Robert and Clara are happily married with a small child. George lives with them, and little George visits them frequently. Lady Audley died in Belgium. Sir Michael and Alicia no longer live at Audley Court, and the house is shut up. Alicia is engaged to Sir Harry Towers, and Sir Michael will live near by after the marriage. Everyone is happy and at peace, and there is even the implication that George Talboys may find a new partner someday.
The question of madness continues to predominate. Dr. Mosgrave's diagnosis mostly supports the idea of Lady Audley as a villain: he believes that she is rational, and acts for her own benefit. He also believes that she can easily behave in violent ways and that it is important that she be placed somewhere where she cannot hurt anyone. At this point, however, Lady Audley has not confessed to any violent crimes and Robert does not want the public scandal of a trial, especially if it will not result in a conviction. Lady Audley's punishment is therefore handled in a private way. While on the one hand, it may be a satisfying example of poetic justice for her to be placed in a madhouse, after she threatened to do the same thing to Robert, it is also somewhat disturbing how easily she can be institutionalized. This draws attention to how much power her husband (or his appointed representative in the form of Robert) has: while in Lady Audley's case, she arguably deserves to be locked up, it is not hard to imagine that this could also happen to a woman who didn't.
Other secrets continue to unfold; Lady Audley finally tells Robert what happened between her and George. Surprisingly, after all the time he has put into investigating the mystery, this information does not bring Robert any peace. He wants to lay his friend's body to rest, but that will not be possible without a public scandal and further suffering and embarrassment for Sir Michael. It is ironic that it appears here that the resolution of the secret won’t make a difference after all.
However, Luke's story offers one of the biggest plot twists of the novel. While Luke has seemed like a relatively unimportant character, and Robert has always assumed that it would be Lady Audley's confession that would resolve the plot, it turns out that it is Luke's secret that has the biggest impact, and that he has known information that even Lady Audley did not have about the true events around George's disappearance. Robert shows his compassion in telling her that George is still alive, hoping that it will help her to find peace. Indeed, Lady Audley's death is surprisingly quiet and peaceful. While her crimes and lies might suggest a more dramatic kind of punishment, Braddon's choice to let her die in peaceful obscurity without ever being publicly shamed furthers the idea that there is some sympathy for her present in the novel.
Now that Robert no longer has to be obsessed with his quest, he can focus his energies on courting Clara. Their engagement and future marriage shows signs of being one of the few relationships in the novel that is happy and founded on a fair and balanced partnership. The two plan to go to Australia together to look for George, suggesting that Clara will be able to maintain her agency and be a contributing partner in this relationship.
However, in a somewhat anti-climactic moment the voyage proves unnecessary because George makes his way back to London. After all the drama and effort that has gone into looking for him, it is ironic that he reappears simply because he feels like it. It does, however, allow for a happy and peaceful resolution. The close of the novel emphasizes domestic happiness: Clara and George have formed a happy family unit, and Alicia is about to do the same with Harry Towers. However, there are still a few subversive hints. Robert, Clara, and George all live together, suggesting that the relationship between the two men is equally important to the relationship between Robert and his wife. Moreover, at the end of a novel that has worked so hard to show that even the most seemingly happy circumstances can be home to dark secrets, the presentation of happy marriages ends the novel on a partially ironic note.