I loved the Mysterious Benedict Society series. The MBS trilogy
tells the adventures child prodigies Reynie (a logic master), 
Sticky (a
bald kid with a photographic memory), Kate (a circus strong-girl with a
bucket of tricks instead of a utility belt), and Constance (age 3,
feisty as heck, and able to know what you're going to do even before you
do). They and the mysterious Mr. Benedict battle the dark forces of
Ledroptha Curtain and his support staff--the Ten Men and their
briefcases of death.
