"The magic tree house whisks Jack and Annie away to Greenland where they discover they've traveled back in time to meet Lief Erikson"--

Soon after being recruited by the mysterious Mrs. Boudica to join a secret military intelligence operation, Josie, Mae, and Akiko discover their superhero abilities and use them to thwart a Nazi plot to steal the ENIAC computer.

Eleanor and her mother Samantha are working seperately and preparing for a journey to find the Master Concentrator when an alien spacecraft lands on Earth and throws the globe into a crisis that Eleanor works to control.

Alex is an apprentice librarian in a kingdom that keeps all the books locked up but doesn't know if it's to keep the books safe from readers or... to keep readers safe from the books! When the royal librarian suspiciously dies, Alex impersonates the old man so the young queen won't know who he really is. She gives the scruffy, obnoxious boy enough time to prove himself-- and enough time for them to learn that the books are more than just powerful,...

Having defeated the Garr, a vicious tree monster who lived within the enchanted woods of Watch Hollow, Lucy and Oliver Tinker now have the home they've always dreamed of: Blackford House. Powered by a magical clock and full of curious rooms and improbable knickknacks, Blackford House brims with the promise of new adventures. Yet when a strange governess arrives from England--bringing with her the Kojima twins, Agatha and Algernon--the Tinker children's...

Ascendant King Jaron believes that his kingdom, Carthya, is at peace, so he and his bethrothed, Imogen, are sailing home from a trade mission when their ship is attacked by Prozarians, and Jaron and several of his friends are taken prisoner; the Prozarian captain seems to believe he had something to do with his parents' deaths and they also know a great deal about Jaron's long-missing older brother, Darius, the rightful heir to Carthya--who may be...

Twelve-year-olds George, the very unlucky third Lord of Devonshire, and his neighbor, scientist Ada Byron, join forces against a nefarious group of criminals who steal the map to a priceless family heirloom.