Emmaline lives in a castle-turned hospital for children displaced by WWII in the UK, a gray place where many come to stay, but most never leave. Emmaline can see beautiful winged horses in the castle's many mirrors and believes there is a secret land just on the other side of these reflective surfaces. Emmaline's world collides with the the land of the horses when she finds a beautiful white horse with a damaged wing in the castle's garden. She also finds a note from the Horse Lord begging her to find special objects to help protect Foxfire from the sinister Black Horse who has also crossed over into Emmaline's world.

A lyrically masterful novel for mid-grade readers, I adored how you never quite found out if the horses were an object of Emmaline's fantasies, spurred by her own illness that slowly becomes more apparent to the reader as the pages go on, or if they were indeed real. The ending is also ambiguous enough that readers can draw their own conclusions on the fate of Foxfire and Emmaline.

Both hauntingly sad and beautiful, this is a perfect book for both adults and more mature mid-grade readers, akin to The Secret Garden or The Little Princess.