The name of this book is secret by Pseudonymous Bosch - Two eleven-year-old misfits try to solve the mystery of a dead magician and stop the evil Dr. L and Ms. Mauvais, who are searching for the secret of immortality
Assassin by Grace Cavendish - Thirteen-year-old Lady Grace Cavendish, favorite maid of honor of Elizabeth I, must solve a murder mystery and clear the name of her betrothed
The wig in the window by Kristen Kittscher - When their game of neighborhood spying takes a dark turn one night, pre-teen sleuths Sophie Young and Grace Yang find themselves caught in a dangerous cat-and-mouse game with their bizarre guidance counselor
The view from the cherry tree by Willo Davis Roberts - Rob admits having seen a murder, but no one believes him—except the murderer
The Westing game by Ellen Raskin - The mysterious death of an eccentric millionaire brings together an unlikely assortment of heirs who must uncover the circumstances of his death before they can claim their inheritance
The mysterious Benedict Society by Trenton Lee Stewart - After passing a series of mind-bending tests, four children are selected for a secret mission that requires them to go undercover at the Learning Institute for the Very Enlightened
The Egypt game by Zilpha Keatley Snyder - A group of children, entranced with the study of Egypt, play their own Egypt game, are visited by a secret oracle, become involved in a murder, and befriend the Professor of the local junk shop