Twins Theo and Alexander, their older sister Wil, and five new friends find themselves at an electrifying manor run by Mister Frank and Dr. Stein.

"It's hard to wait for an exciting new baby to join the family, especially when it's still growing inside Mom's tummy. But when her dad tells her the size of the baby at each stage, one little girl imagines all the fun she can have with her baby brother as a teeny-tiny poppy seed, then a grape, then a lemon... but she's not quite sure how she feels about having an avocado for a brother. Or an onion. Or--gulp--a watermelon!"--

Twins Theo and Alexander and their sister Wil are abruptly dropped off at their Aunt Saffronia's house, where they learn they must complete a series of tasks in order to see their parents again--and their first assignment is at a waterpark.

Jack and Annie travel to a monastery in the Swiss Alps where, with the help of St. Bernard dogs and magic, they seek the second of four special objects necessary to break the spell on the wizard Merlin's beloved penguin, Penny.

"When 12-year-old Dory Byrne's pop left New York City's Lower East Side to fight Hitler, he promised her and her brothers that they'd be safe. Like he always said, "the neighborhood will give you what you need." There's the lady from the bakery, who saves them leftover crullers. The kind landlord who checks in on them. And every Thursday night, the Byrnes enjoy a free bowl of seafood stew at Mr. Caputo's restaurant. . . which is where Dory learns...

The Melendy family moves to a house in the country where a secret room, a cupola, a stable, and a book provide Mona, Rush, Randy, and Oliver with adventures far different from the city life to which they are accustomed.

"Theo and her brother, Marco, threw the biggest party of the year. And got caught. Their punishment? Leave Arizona to spend the summer with their grandmother in the rainy beachside town of Nightfall, Oregon--population 846 souls. The small town is cute, when it's not raining, but their grandmother is superstitious and strangely antisocial. Upon their arrival she lays out the one house rule: always be home before dark. But Theo and Marco are determined...

"Jack and Annie travel back in time to 1925 Nome, Alaska, where they meet Balto, the famous sled dog, and help save the town from illness"--

Amy and Dan Cahill have been located once again, this time in the company of the notoriously unreliable Alistair. Spies report that Amy and Dan seem to be tracking the life of one of the most powerful fighters the world has ever known. If this fearsome warrior was a Cahill, his secrets are sure to be well-guarded.

Throughout the hunt for the 39 Clues, Amy and Dan Cahill have uncovered history's greatest mysteries and their family's deadliest secrets, but are they ready to face the truth about the Cahills and the key to their unmatched power? After a whirlwind race that's taken them across five continents, Amy and Dan face the most the difficult challenge yet -- a task no Cahill dared to imagine. When faced with a choice that could change the future of the world,...