Eight-year-old spy Adam Sharp pursues the very short Ambassador of Barkastan, who has stolen a top secret computer program, DOGBARK, that will let him understand the language of dogs.

Matilda "Wheezer" Choi, an asthmatic who uses nanobyte-enhanced inhalers and hates anything girlie, must infiltrate the cheerleading squad when former member of NERDS turned villain, Gerdie Baker, becomes a cheerleader and starts pillaging other worlds with the assistance of a device the criminal mastermind Simon helped her make.

Hazel Kaplansky is a firm believer in the pursuit of knowledge and truth-and she also happens to love a good mystery. When suspicions swirl that a Russian spy has infiltrated her small town of Maple Hill, Vermont, amidst the fervor of Cold War era McCarthyism, Hazel knows it's up to her to find a suspect... starting with Mr. Jones, the quietly suspicious grave digger. Plus she's found a perfect sleuthing partner in Samuel Butler, the new boy in school...

In 1776, fifteen-year-old Francisca escapes a dangerous life in the Bahamas by posing as a wealthy shipwreck victim, and soon finds herself a spy for George Washington in New York.

Whisked back to 1863 Virginia with the aid of a magical spyglass, the three Chapman children meet real-life Civil War spy, John Doyle.

Fighter pilot Spensa Nightshade has been embroiled in an alien empire's war and now, to figure out what she really is, she must leave her world behind to enter the Nowhere, a mysterious realm from which those who enter rarely ever return.