America's most celebrated astrophysicist invites young readers to explore the mysteries of the universe.

When demons begin appearing on Earth unpredictably, foreshadowing a cataclysmic breakdown of their magic, Artemis and his friends face a new foe--a twelve-year-old girl whose intellect just might match Artemis's own--as they try to prevent catastrophe.

Artemis's mother has contracted a deadly disease -- and the only cure lies in the brain fluid of African lemurs. Unfortunately, Artemis himself was responsible for making the lemurs extinct five years ago. Now he must enlist the aid of his fairy friends to travel back in time and save them. Not only that, but he must face his deadliest foe yet...his younger self.

In the Welsh hills Will Stanton, youngest of the immortal Old Ones, joins forces with Merriman, Bran, and the mortal Drew children in a quest through space and time against the powers of evil known as the Dark. The most ancient myths of Britain are evoked as Will and Bran search for the crystal sword that alone can vanquish the Dark.

Presents the continuing adventures of Henry York, who has been living in Kansas with his cousins, where he discovers doorways leading to other worlds and becomes involved in a multi-world struggle between good and evil.

As time plays tricks and night falls without warning, Johnny, Dizzy, and Charlie, who are lost in the woods, must elude the danger that lurks in shadows and work together to find a way out. Includes note about the science behind the story.

"Teenage genius Artemis Fowl and his arch rival Opal battle to the last in this eighth and final book in series"--

Teenaged criminal mastermind Artemis Fowl must save the underwater fairy metropolis of Atlantis from danger, while battling a psychological affliction known as the Atlantis Complex.

Continuing their adventures through space and time, Ben and his faithful dog, Ned, find themselves in the Mediterranean region in 1703, befriended by a troupe of traveling entertainers and relentlessly pursued by ruthless Barbary slave traders.

Science-loving Delia Bean is expecting to have a pretty boring summer vacation looking after her little brother. But when her Uncle Lyndon offers her an internship in his Earth Time Museum, everything begins to look a lot better!