Andrew, his cousin Judy, and Thudd the robot, having been shrunk by a shrinking machine, encounter many terrifying creatures, including Mrs. Scuttle, as they try to reach the Atom Sucker before it explodes.

After being shrunk by a shrinking machine and ending up on a dog having a bubble bath, Alexander, his cousin Judy, and a tiny robot try to survive encounters with insects, soapy bubbles, and bathtub and toilet drains.

Andrew, his cousin Judy, and Thudd the robot wind up at a garbage dump when Andrew's latest invention, the Goa Constrictor, shrinks them to the size of beetles and swallows them.

Still reduced to the size of insects, Andrew, Judy, and the robot Thudd go to a pond, where they encounter dragonflies, moss animals, and fierce larvae in an attempt to learn why frogs are disappearing throughout the world.