Helen Plum Library

At the reading of their grandmother's will, Dan and Amy Cahill are given the choice of receiving a million dollars or uncovering the 39 clues hidden around the world that will lead to the source of the family's power, but by taking on the clues, they end up in a dangerous race against their own family members

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,...

Seven-year-olds Bradley, Brian, Nate, and Lucy make observations and gather clues that convince them that their older siblings, cousin, and animals have been captured by hungry space aliens

"Amy and Dan Cahill have been located once again, this time in the company of the notoriously unreliable Alistair Oh. Could they have been foolish enough to make an alliance? 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 . . . and the price to uncover them just might be lethal."--Publisher

Orphans Sabrina and Daphne Grimm are sent to live with an eccentric grandmother whom they have always believed to be dead

Nate the Great investigates two cases that may be connected, involving a missing valentine and a valentine that came from nowhere

Hoping to become the greatest detective that ever grew, Inspector Flytrap, a Venus Flytrap, and his assistant, Nina the Goat, investigate "big deal" mysteries at an art museum, a cookie shop, and a garden

When a puppy who is being trained as a police dog goes missing, third-grader Judy forms a detective agency to solve the mystery, imitating her literary heroine, Nancy Drew

"A terrible crime forces Lockwood to turn to Lucy for help, setting them on the trail of dark secrets at the heart of London society. Both professionally and personally, their investigation stirs up forces they may not be able to control. . ."--

Thirteen-year-old Dan Cahill and his older sister Amy race against time to find an ancient map that has not been seen for half a century and use it to redeem their family members who have been kidnapped by a sinister organization called the Vespers