The cuckoo is not known for euphony. Cuckoos are famous primarily for the thing that makes them a magnificent middle-grade biology lesson: their tendency to lay their eggs in other small birds' nests, so that unknowing other-species parents devote food and attention to offspring which is diverting resources from their own genetic products. In the middle-grade biology classrooms of my acquaintance, this is represented as a nasty trick, even though it has no conscious perpetrator. Isn't it possible, the students wonder, that somehow the cuckoos could . . . not be like that? The picture of the other chicks, abandoned and hungry while in the very presence of devoted parental efforts to care for them, is heartwrenching.

Frances Hardinge's new novel, Cuckoo Song, wonders what rights the cuckoo chick has in the situation.

If we weren't tipped off by the title, it might be difficult to figure out what the problem is with eleven-year-old Triss, Hardinge's protagonist. She fell into a river, returned soaking wet and shivering, and ever since, everything has been different. There are strange gaps in her memory. The pages of her diary have been torn out. Her younger sister, Pen, refuses to come near her. Crumbs of earth fall onto the floor from her feet, and dead leaves clog her hairbrush. But her loving parents insist that everything is going to be all right and take her to many, many doctors. The doctors can't do much, since it is the early 1920s, and there are no sophisticated scans, not even antibiotics. The parents watch in mounting confusion and horror as the evidence mounts that whatever Triss is going to be, all right is not an accurate description. Their fear is matched and then surpassed by Triss's own.

This part of the novel, approximately the first third, is gripping psychological horror of a sort particular to young women. Triss is possessed by the sense that her body is not her body, her family is not her family, and that everything she has found comforting and familiar is a lie because she has been seeing it from the wrong angle. She doesn't know who she is, but she's worried that whoever or whatever she turns out to be will be unacceptable to her family, unlovable, unnecessary, and unwanted. That her parents have been keeping her smotheringly close to them since the death of her elder brother in World War I, while making Pen the scapegoat for everything, does not soothe Triss's worries. The fact that she's right—her family is not her family, her body is not her body, and she herself is a thing without a name, from elsewhere—heightens rather than assuages the discomfort and disruption of her state seen as a metaphor for growing up female.

We begin to get the sense that Triss would have had to have these conversations, feel these fears, and break out of these patterns whether or not the supernatural had ever intruded; that the thing that has happened dictates the timing, but not the content. Menarche might well have been enough to cause this on its own, which, since she is also absolutely right that what she has become is unacceptable and unwanted to her family, is utterly chilling as a depiction of the contingent and tenuous position into which family and society all too often force young girls. It's not an accident that Hardinge's novel is set in the twenties, in precisely the years in which it was legal for women over thirty who owned property to vote in Britain (which began in 1918), but before the franchise was extended to every woman over twenty-one (in 1928). This was a time in which women who had gone into many spheres of the workforce during the World War were wondering what they should do with themselves. Many of these women had found they had capacities and aptitudes they never expected, and that staying quietly at home was no longer attractive or even tolerable. Triss's parents, old-fashioned, patriarchal, genuinely wanting the best for their daughters but with no idea of what that is, do not know how to raise a girl who doesn't want to do what they say—and cannot face the reality of a daughter who snoops on their telephone conversations and literally eats all the food in the house. Triss's supernatural traits are brilliantly calibrated to keep worsening the situation and making the metaphor more unpalatable, until, as it has to, the whole situation explodes. The story leading up to the explosion is one of the most deeply uncanny pieces of fiction I have read in a very long time.

The following two-thirds of the novel are also wonderful, but belong to an entirely different genre, and although Hardinge has successfully made the book as much of a unified whole as it can be, she can't help but lose the emotional intensity that came from claustrophobia. Once Triss has confirmation that she is Not-Triss, that she is a changeling, it's fair that there's a lot more story after that, because of the question of what happened to the original, and the question of what Not-Triss should do or become other than Triss. In fact, since Not-Triss is the sort of changeling which has a strictly limited lifespan after having been substituted, literally made of twigs and dirt and not wishing to become twigs and dirt again, it's more than reasonable that most of the story is set after she's found out her true nature. I have not before encountered this kind of changeling story told from the viewpoint of the changeling.

When Not-Triss's world widens, it includes the town she lives in, Ellchester, a fictional confection of a place strung over incredibly steep hills and water, tied together only with bridges; Violet, her brother's fiancée before he was killed, a New Woman with a motorcycle and a lingering trauma; the mysterious beings called Besiders, who made Not-Triss in the first place; and Pen, full of dogged determination to fix everything and get back her real sister. Almost no one is on Not-Triss's side as she tries to piece together scattered information about her origins and purpose, dodge those who know she is a changeling and consider her a monster, dodge those who don't know she's a changeling and consider her a runaway or kidnapped child, and figure out something to do about her upcoming dissolution. This part of the book is an extremely well-crafted, complicated mix of personalities and factions, carried out with Hardinge's typical care for rounded characters and non-stereotypical motivations. It has action, humor, and drive, it consistently doesn't go where it might be expected to, and it presents Not-Triss with a series of genuinely difficult and frightening challenges while also making her reactions to those challenges believable. What it doesn't do, from my perspective, is successfully extend the metaphor the book maintained so gracefully in its earlier portion.

Hardinge tries nobly to keep her symbolism going, and does in fact successfully surmount one of the greatest obstacles to doing so, which is that it is difficult for a large and mobile cast of very individual characters to be as representative of generalized human experience as one single character can be. She takes the more than respectable route of producing characters who can be seen as themselves, but also as facets of the experiences that a woman who has broken free of a stifling house and family might have. There's Not-Triss, a creature of growing confidence and growing fear, who becomes powerful insofar as she embraces her strangenesses. There's Violet, who has simply thrown over the conventions, but who can't help wishing it had all gone differently. There's Pen, who is enough of a child sometimes to be unable to grasp the severity of what is happening, but who also derives a deep pleasure from simply being out in the world with people she finds congenial. There's the girls' mother, Celeste, who delegates everything to her husband and walks away from the worst of it all, allowing others to commit horrors in her name and for her sake. And lastly, there's the real Triss, imprisoned, abandoned, remembered by very few, and in continuous deadly danger. Taken as a whole, they almost continue the metaphor—the girl in the beginning could have grown into this, or this, or, if everything went wrong, this . . .

But the difficulty here is that a few of the most crucial viewpoints are not sufficiently three-dimensional. For example, we see Celeste fail in her responsibilities to her daughters and her responsibilities as a human being, and we see her fail in ways that clearly happen because of the patriarchal nature of the family structure which allows her to abdicate her own life. But we don't see enough of her as a person, apart from her family, to understand why she dives into convention and stability and stays there. We're told of her great grief at the death of her son, but since Triss's father is the more active in taking Triss/Not-Triss to doctors and so forth, we see more of the way he is wrapped up in his loss and turning that onto Triss/Not-Triss than we see of Celeste doing the same. As a result, it's not really possible to empathize with Celeste, which, in a novel so devoted to the perspective of the outsider, consideration of ways people are forced into conformity, and the wrenching pressures put on women, is a significant flaw. Not-Triss, we are told, could not have grown up into Celeste. But we are not shown why she could not.

This is, however, minor compared to the book's real strengths, which wed action scenes and character depth using subtlety and power. Cuckoo Song is not the best of Hardinge's novels to date (that honor probably goes to Gullstruck Island [2009]), but it pulls off its difficult and ambitious goals with only that ungainly genre-switch in the middle as its major perceptible flaw, and that becomes less a flaw and more a need to recalibrate expectations after one sees what Hardinge does with the rest of the book. Cuckoos, as I mentioned, are not known for euphony. They are, however, named for their cry, and the distinctive noise they make has spawned an entire clock industry with the cuckoo at its center. The cuckoo chick, as other chicks do, cries out for food and care and attention and love from its parents, and understands no reason why it should not receive them. For this novel, and for Not-Triss, being able to articulate the cry is just enough.

Lila Garrott has blue hair and brown eyes. Her fiction, poetry, and criticism have appeared in Not One of Us, Mythic Delirium, and other venues. She recently completed a project in which she read a book and wrote a review of it every day for a year; the reviews may be found on Dreamwidth and LiveJournal.