Ellie's scientist grandfather has discovered a way to reverse aging, and consequently has turned into a teenager--which makes for complicated relationships when he moves in with Ellie and her mother, his daughter.

It is 1943, and 11-year-old Dewey Kerrigan is traveling west on a train to live with her scientist father--but no one will tell her exactly where he is. When she reaches Los Alamos, New Mexico, she learns why: he's working on a top secret government program.

Young secret agent Amelia investigates three new cases, involving an evil genius who makes dogs howl, a sneaky science teacher who buys too much cereal, and a psychotic criminal picking the pockets of toy shoppers.

Elementary school secret agent Amelia continues her efforts to save the world from evil geniuses and criminal masterminds, this time foiling a jewel thief, identifying some unusual cat burglars, and evading a weed army.

Kat is reluctant to visit her Uncle Vic Frankenstein because of all the rumors about him. People in the small town where he lives say he's a mad scientist like his great-grandfather, Victor Frankenstein, who created a monster that came alive and terrorized the town. But Kat is relieved to find that even though he lives in a dark, old castle-like mansion, Uncle Vic is a quiet, gentle man, a scientist interested in building robots with artificial intelligence....

When, in the process of testing his newest time machine, Professor von Volt accidently brings a triceratops, Helen of Troy, Attila the Hun, Charlemagne, and Christopher Columbus to present day New Mouse City, it is up to Geronimo and his friends to return them all to their own times and places--without being eaten by a T-Rex or skewered by Trojan warriors.