I would definitely consider this lower middle grade, for 8-9 year old kids. Maybe a good transition from chapter books.

11-year-old Cora Flash is taking her first solo train trip up to Topaz Mountain. On the way, she meets and befriends a small group of travelers. All is well until a valuable diamond is stolen, and the culprit must be one of the group. As the investigating detective begins his interrogations, Cora realizes the man may be on the wrong track, and it may be up to her to find the thief and the diamond before it’s too late.

What I liked: cute mystery, with a Murder on the Orient Express motif (minus the murder). It’s a fast read with identifiable characters. I lik

What I didn’t like: the beginning is slow, not much really happens, and the mystery itself doesn’t begin until the end of chapter 4. But what bothers me the most is the way Cora talks—she speaks like an adult. No 11-year-old that I know says things like “I made a mental note of this trivial detail” or “I woke up in the morning feeling refreshed” or “my hunch was incorrect.” Her speech throws her character off, like she should be quite a bit older, but her actions are definitely those of an 11-year-old.

3.5 out of 5 stars