"Jack and Annie are ready for their next fantasy adventure in the Magic Tree House series! Where did the tree house come from? Before Jack and Annie can find out, the mysterious tree house whisks them to the prehistoric past. Now they have to figure out how to get home. Can they do it before dark...or will they become a dinosaur's dinner?"--

Twelve-year-old David and his family search for their kidnapped mother in the many different time period portals of their home, but when a stranger appears and tries to force them to sell the house, their desperation reaches new heights.

In Victorian London, Albert Garrick, an assassin-for-hire, and his reluctant young apprentice, Riley, are transported via wormhole to modern London, where Riley teams up with a young FBI agent to stop Garrick from returning to his own time and using his newly acquired scientific knowledge and power to change the world forever.

As Daniel X continues to hunt for intergalactic aliens, he and his friends go to England searching for Beta, an outlaw who takes the form of fire and who killed Daniel's parents when he was two years old.

Sam Faulkner travels back in time to medieval Ireland, ancient Egypt and Renaissance Bruges in search of his missing father.

Two teenagers use H. G. Wells's famous time machine to race through time and stop a dangerous enemy.

"Em must travel back in time to prevent a catastrophic time machine from ever being invented, while Marina battles to prevent the murder of the boy she loves"--

Time travel, a computer virus that's deadly to humans, and other strange things begin to happen when some would-be witches come to stay with the eccentric Strega-Borgia family.

"In this volume, fifteen-year-old Charles Wallace and the unicorn Gaudior undertake a perilous journey through time in a desperate attempt to stop the destruction of the world by the mad dictator Madog Branzillo. They are not alone in their quest. Charles Wallace's sister, Meg, grown and expecting her first child, but still able to enter her brother's thoughts and emotions by "kything", goes with him in spirit. Charles Wallace must face the ultimate...

Esmeralda, who is both a princess and a powerful witch, must travel back in time to end a family curse or risk losing her true love, Prince Eadric, forever.