Two scientists want to take over the world by cracking the code of baby language using a gifted baby. When the wrong twin is captured for their experiments the other rallies the other foster babies to squash their plans.

Twin sisters switch places when a soccer tournament lands them on mismatched teams and end up creating chaos both on and off the field.

Two identical twins separated since their parents' divorce are up to their freckles in schemes and dreams to switch places, get their parents back together and have the family they've always wished for.

"It's been five years since the Mason family vacationed at the lakeside cottage in northeastern Vermont, close to where prize-winning novelist Samuel Mason grew up. The summers that Sam, his wife, Mena, and their twins Franny and Finn spent at Lake Gormlaith were noisy, chaotic, and nearly perfect. But since Franny's death, the Masons have been flailing, one step away from falling apart. Lake Gormlaith is Sam's last, best hope of rescuing his son...

When twins Lottie and Mia meet a boy named Max who may be a bully, they use their special super twin powers to save the day.

Identical twins Payton and Emma continue to navigate life in middle school as they serve their punishment for having fooled people by trading places, and they learn that their own identities are usually best.

While working at pleasant but mundane summer jobs in San Francisco, fifteen-year-old twins, Sophie and Josh, suddenly find themselves caught up in the deadly, centuries-old struggle between rival alchemists, Nicholas Flamel and John Dee, over the possession of an ancient and powerful book holding the secret formulas for alchemy and everlasting life.

An exploration of nature versus nurture follows the unique case of two sets of identical twins, who, born in Colombia, were separated at birth and improbably reunited as adults.

Bradley, Brian, Nate, and Lucy try to help out the Flying Fortunatos, an acrobatic troupe with a very shabby traveling circus, by identifying the marvelous, hooded trapeze artist they spied rehearsing.