Russian immigrant Anya, who just wants to fit in and be popular at school, falls down an old well in the woods and encounters the skeleton--and the ghost--of Emily Reilly. Somehow a fingerbone of Emily's gets into Anya's bag, so when Anya is rescued, Emily can go with her. At first, after Anya gets over the shock, having a ghostly friend is a great help--Emily can find things out for Anya and help with her homework. Soon, though, it seems that Emily wants to push Anya in a direction she doesn't want to go--and that she'll do anything to get Anya to do what she wants.
This book got fantastic reviews, and it deserves them. Its great strength is that Anya is so believable. She's a completely self-absorbed teen trying to shed her culture and her annoying family in favor of catching the eye of the hot basketball star at school, but she's still sympathetic--we've all been there in one way or another! Her realizations about not just Emily, but herself and her family, come about realistically and believably. I don't like ghost stories, but this one was really well-constructed.