At nearly fifteen years of age, Joey Harker learns that he is a Walker, able to travel between dimensions, and soon joins a team of different versions of himself, each from another dimension, to fight the evil forces striving to conquer all the worlds.

"While picking up milk for his children's cereal, a father is abducted by aliens and finds himself on a wild adventure through time and space."--Publisher's description.

The fate of the multiverse rests in Marguerite's hands in the final installment of the Firebird trilogy by New York Times bestselling author Claudia Gray. Ever since she used the Firebird, her parent's invention, to cross through alternate dimensions, Marguerite has been at the center of a cross-dimensional feud. Now she has learned that the evil Triad Corporation plans to destroy hundreds of universes, using their ultimate weapon: another dimension's...

When an all-consuming void from the Fourth Dimension opens up, unleashing monsters throughout the Realities, Mister George has one last weapon at his disposal--the mysterious and powerful Karma button, which might be even more dangerous than anyone imagined.

Four cousins, Roger, Ann, Eliza, and Jack, have an extraordinary summer when, after an old toy soldier comes to life, they find themselves transported back to the days of Robin Hood and Ivanhoe.

After mastering the ability to walk between dimensions, sixteen-year-old Joey Harker and his fellow InterWorld freedom fighters embark on a mission to maintain peace between the rival powers of magic and science who seek to control all worlds.

After plummeting through a hole in her backyard and finding herself once again in the room of mysterious jars, eleven-year-old Olive unwittingly releases two of Elsewhere's biggest, most cunning, most dangerous forces.

Fourteen-year-old Jason Walker is transported to a strange world called Lyrian, where he joins Rachel, who was also drawn there from our world, and a few rebels, to piece together the Word that can destroy the malicious wizard emperor, Surroth.

Thirteen-year-old Atticus "Tick" Higginbottom begins receiving mysterious letters from around the world signed only "M.G.," and the clues contained therein lead him on a journey to the perilous 13th Reality and a confrontation with evil Mistress Jane.

After Jason succeeds in finding a way back to Lyrian, he's immediately in more danger than ever. Meanwhile, Rachel and the others have made their own progress--as well as discovered new enemies. As the group ultimately rejoins, they strive to convince their most needed ally to join the war and form a rebellion strong enough to triumph against the emperor.