There's a new resident in Castle Key - and somebody is watching him! Scott, Jack, Emily and Drift soon suspect that the new resident is an enemy spy. It explain

X-Men meets Spy Kids in the thrilling second installment in The Forgotten Five fantasy/adventure series that began with the instant New York Times bestseller Ma

X-Men meets Spy Kids in this instant New York Times bestseller! Here’s the first book in a new middle-grade fantasy/adventure series from the author of The Un

When someone takes Justin's karate belt, his friends in Invisible Inc. try to determine a motive as they investigate the mystery.

Dead drops, cyphers, and invisible ink are all part of a mystery that even spymaster George Washington would love. Sam, Derek, and Caitlin love solving mysterie