Wendy Mass

This time a strange flashing cube from the magic suitcase sends them to a nearby city, Hadenstown, in the future, and they find themselves surrounded by flying cars, tall glass buildings, and robots; but Randall is also there, and the two children must scramble to figure out just what the mysterious cube is and get it back where it belongs--and their quest brings Chase face-to-face with his future self, Professor Teslar.

On a visit to the Natural History Museum, Chase and Ava seem on the verge of finding out something important about the mysterious Randall, the missing scientist Finn, and the woman who gave them the suitcase filled with magical objects, when the dinosaur egg from the suitcase (they thought it was a potato) sends them back to dinosaur times--where they have to return the egg to the correct brontosaurus nest, while eluding hungry dinosaurs, and Randall,...

"Eight-year-old Archie Morningstar, his father, and the talking cat Pockets travel to a planet that closely resembles medieval Earth in order to rescue a princess from the clutches of the intergalactic criminal organization B.U.R.P. Includes fun science facts to impress your friends and teachers!"--

"Eight-year-old Archie Morningstar, his father, and the talking cat Pockets travel to Akbar's Floating Rest Stop, where Pockets is going to receive an award for bravery. But when all the tuna fish (Pockets's favorite food) goes missing, they must discover who is behind the nefarious plot"--

A look at the historical roots of the holiday Halloween and how it developed into the modern celebration.

The Voyagers have made it to the last planet but must acquire a seventh element, combat dragons and an alien clone, and face serious illness before returning to Earth.

When a mysterious Little Free Library guarded by a large orange cat appears overnight, eleven-year-old Evan plucks two weathered books from its shelves, never suspecting that his life is about to change.

Some mild thematic elements. Just before his thirteenth birthday, Jeremy Fink receives a keyless locked box--set aside by his father before his death five years earlier--that purportedly contains the meaning of life.