I just read Cuckoo Song, another YA book by Frances Hardinge, since I liked The Lie Tree so well.
The setting of this one is England shortly after World War I.
Young “Tris” (short for Theresa) wakes up sick and confused in her bed, after an “accidental fall” into the river. The doctor called in by her hovering parents assures her that a fragmentary memory is natural under the circumstances, and all that she needs to fully recover is rest and quiet.
But to Tris, there is much more wrong than simply lost memories. She doesn’t feel like those pieces of her life that she does recall are really hers, she has a voracious appetite (not just for food but also for dolls and trinkets, objects which she swallows whole) ... and oh yes, her younger sister hates her. That’s nothing new, but now eleven-year old Penn accuses her of “pretending.” Pretending to be what? Pretending to be Tris.
It’s a challenge to discover the truth without upsetting her over-protective parents, who are clearly harboring secrets of their own, but gradually Tris comes to understand that she is not Theresa Crescent at all. She’s a changeling, magically created out of sticks and paper and leaves and vines to resemble and replace the real Tris, who has been kidnapped by the mysterious “Besiders.”
As the false Tris endeavors to rescue her namesake, the situation becomes increasingly desperate. For a terrible fate awaits the real Tris at the hands of the Besiders, and the spell that animates her would-be rescuer only lasts for seven days—and most of that week is already gone.
For all the supernatural events and characters, this is a realistic portrait of a dysfunctional family, dealing (very badly) with the traumatic loss of a son who never returned from the war. The writing is skilled and often poetic, as Hardinge uses vivid details of the mundane world, circa 1923, to contrast and blend with traditional folklore.