1. The Last Little Blue Envelope by Maureen Johnson
I think this is technically an adult book, but I recently gave it to a teenager who loved it.
3. The Case of the Missing Marquess by Nancy Springer (middle grade)
BOOKS SUGGESTED BY MY BLOG READERS:
No Place Like Holmes by Jason Lethcoe (suggested by Jaguar Hero!)
The Girl in the Steel Corset by Kady Cross (suggested by Tressa @ Tressa's Wishful Endings)