(2) 4-6 Following their mother's death, thirteen-year-old Gwen, her younger siblings, and stepfather Henry move to Gloam Island to live in the children's late grandmother's house, which seems spookier than when Grandma was alive. Because Henry has to get a job on the mainland, he hires a strangely captivating babysitter; Gwen immediately distrusts Esme, but no one else in the family can see how manipulative and cruel she is when they're alone. Then a cat leads Gwen to the old willow tree Grandma used to talk to, and the willow divulges Esme's true nature and the lengths to which she will go to feast on the children's fears. The tree also gives Gwen a key that holds the secret to defeating Esme -- if the children can keep it out of her grasp. The nightmare fuel that Mackay brings to bear against each of the children draws brilliantly on phobic triggers and the terror of the unknown. A focus on the nature of courage ("It is impossible to be brave if you are not already afraid") and the tendency of adults to disbelieve children's lived experiences make the story highly pertinent. Machinations around the key give the book an easily grasped structure, but it's the atmospheric effects -- an old house, childhood fears not quite outgrown, sibling dynamics exploited by a malevolent force -- that will keep readers up at night.

Reviewer: Anita L. Burkam | Horn Book Magazine Issue: September, 2025