Iris and her identical twin sister Lark take care of each other. Well, Iris, the practical twin, takes care of Lark, the dreamy one. And Lark, the imaginative, creative sister, helps Iris deal with her nightmares and anxieties. They “have better outcomes when they’re together.” It’s a workable and loving relationship until the girls’ parents decide that they need to be in separate classrooms for fifth grade. Then Iris loses her confidence, even her sense of identity. Who is Iris without Lark beside her? Lark loses things, as various objects around the house and around town begin to disappear. Iris and Lark are afraid of losing each other, and their fear becomes identified with a strange new antique shop that just opened up across the street from the library. How can the twins make everyone else understand that they need to be together? Or do they need to grow apart?

This book might be profound in a psychological way, but I’m not sure I’m a deep enough thinker to get it. The twins are sort of co-dependent? Maybe co-dependent in a bad way, but by the end of the book they learn to help each other in good ways? It’s sort of dark, and there are some strong feminist girl-power themes and preachiness, but you-go-girl feminism wasn’t overwhelming to the point of being annoying. I did find the story fascinating and compelling. I read it in one day.

This book might win some awards. The last third of the book is particularly creepy and unsettling, but you can reassure frightened readers (yourself?) that the story does end well. And the writing is magical, both literally and figuratively speaking.