The novel begins as the narrator, Jenny, describes her cousin by marriage, Kitty Baldry, pining in the abandoned nursery where her dead first son would have been raised. Occupied with the domestic management of the Baldry estate just outside London, the two are almost completely removed from the horrors of war. The only exception is that Kitty's husband, Chris Baldry, is a British soldier fighting in France. While Kitty laments in the nursery, Margaret Grey arrives at the estate bringing news to the two women. When Jenny and Kitty meet her, they are surprised to find a drab middle-aged woman. And even more to their shock, Margaret tells them that the War Office notified her of Chris's injury and return home, not Kitty and Jenny. Kitty dismisses Margaret from the estate trying to deny that she could have been the recipient of such information.
Soon after, another of Jenny's cousins notifies the two women that he in fact has visited Chris and that he is obsessing over Margaret, whom he had had a summer fling with 15 years before. Soon after, Chris returns shell-shocked to the estate believing he is still 20, but finding himself in a strange world which had aged 15 years beyond his memory. Trying to understand what is real for Chris, Jenny asks Chris to explain what he feels to be true. Chris tells her the story of a romantic summer on Monkey Island, where Chris at the age of 20 fell in love with Margaret, the inn-keeper's daughter. The summer ends with a rash departure by Chris in a fit of jealousy.
After Chris tells this story, Jenny travels to nearby Wealdstone to bring Margaret back to help Chris understand the difference between his remembered past and reality. She arrives at Margaret's dilapidated terraced house to find her dishevelled and taking care of her husband. Jenny convinces Margaret to return with her to the estate to help Chris. Upon Margaret's return, Chris recognises her and becomes excited. Before returning to her home, Margaret explains that 15 years have passed since their Monkey Island summer and that Chris is now married to Kitty. Chris acknowledges this passage of time intellectually but cannot retrieve his memories and still pines for Margaret.
Margaret continues to visit, and Jenny's initial dislike for the woman turns to friendship, gratitude, and eventually, near hero-worship as she realises that Margaret has an inner goodness that transcends her desperate appearance and class standing. Jenny recognises that the artifice of the house she and Kitty have so painstakingly decorated for Chris is a poor substitute for the love and temporary home he finds in Margaret. Jenny spends a lot of the time lamenting her inability to be part of this Chris-Margaret inner sanctum. She grieves the lost closeness with her cousin and expresses admiration for Margaret, Chris and their relationship.
Meanwhile, Kitty continues to despair about Chris's memory loss and his attachment to Margaret. Unlike Jenny, she refuses to speak with Margaret and does not respect the truth that this new/old relationship is doing Chris some good. Truthfully, the only time Chris is happy is when he is with Margaret. Kitty is not satisfied that he cannot be cured and one day announces the impending arrival of a Dr Gilbert Anderson, a psychoanalyst. Dr. Anderson, expected to take a novel tack, arrives during one of Margaret's visits and questions the women. Margaret perceptively recommends a course of treatment: Margaret must confront Chris with the existence of his late son, Oliver, who died at age two, five years ago. Margaret knows Chris will not be able to deny reality if he has to deny his child.
Jenny leads Margaret to the sad, well-maintained room where Oliver once lived. Margaret grieves for her own child whose death at the same age and time as Oliver's makes her feel a connection between the two. Amid this pain, Margaret and Jenny contemplate not "curing" Chris and instead letting him just be happy. But Jenny realises Chris will have no dignity if he has no truth and almost simultaneously, Margaret voices a similar thought.
The final scene of the book has Jenny watching from the house as Margaret confronts Chris with the truth of Oliver. Impatiently, Kitty wonders what is going on. Jenny recognises, even from a distance, that Chris's whole bearing has changed and he is no longer trapped in his youth. He is a soldier again, or as Kitty exclaims "He's cured!" Jenny's silence on the subject leads us to reflect on whether this cure is really a good thing after all. He will lose the love of his life and have to return to the horrors of the war, and, if he survives, the superficial life he has had with Kitty and Jenny.
