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.

As the Wanteds, Unwanteds, and Necessaries struggle to adjust to changes in their society, Mr. Today begins training fourteen-year-old Alex to replace him as Artime's leader one day while Alex's disgraced twin, Aaron, connives to take over Quill.

A sister complains about the way everyone confuses her twin brothers.

Thirteen-year-old Sunny, accompanied by a stray dog, takes advantage of a windfall to travel from her Nebraska foster home to Enumclaw, Washington, to find the twin sister from whom she was separated at age three.

When Princess Dawn sets out on a journey to discover her past, she finds her twin sister Eve and together they realize they can reunite the kingdoms of light and darkness.

Ten years after Alex and Aaron Stowe brought peace to Quill and Artimé, Alex and his Unwanteds set out to rescue his sister, Thisbe, from dragon land leaving her twin, Fifer, behind.

Illustrations and simple, rhyming text explore the joys and challenges of having a twin.

Diana Moore has led a charmed life. But everything is turned upside down when she learns of a mysterious woman who works nearby -- a woman who is her identical mirror image. Diana is compelled to discover the truth about this woman's identity, but the truth leads her down a path of secrets, betrayals, and shocking discoveries about her past. Then she meets Dr. Jacob Peterson and with his help, Diana embarks upon a journey to restore her belief in...

After leaving with the murdered body of her deranged sister, Jack discovers that something has gone very wrong upon her return to Eleanor West's School for Wayward Children.

Magical twins Fifer and Thisbe Stowe have spent their entire lives wishing for an adventure. When a dragon shows up claiming that his family is being kept as slaves in their homeland, the twins sneak off to the land of the dragons to help them.