As far as American Girl books go, this is a gem. Mysteries are not high on my list of preferred genres, but this one had me captivated. I appreciate American Girl writing longer and more substantial books, and I actually learned a lot from this addition to Samantha's story. I didn't know much about the history of elevators or why there are sometimes not a thirteenth floor in hotels. Samantha will always be my favorite American Girl, and I'm still mourning her retirement. Recommended!