Set at America's largest private residence-250 rooms-with real secret passages! Readers learn about the Victorian era when electricity & other "newfangled" things kids take for granted today first came to be. Napoleon, the Vanderbilts, & some of America's greatest writers figure into the plot, as does natural resource conservation.

Christina, Grant, Benjamin, and Katherine become gridlocked in a mystery that takes them on a hair-raising history tour of New York City's most famous landmarks to find a priceless missing part of history.

A trip to see the dinosaurs at the Field Museum uncovers a mystery that sends four kids all over town trying to learn about Chicago's past in order to solve the mystery and save the dinosaurs.

Four kids visit the Underground Railroad museum in Philadelphia and get caught up in a mystery which involves "reading" a quilt.

Grant and Christina investigate the disappearance of a racehorse and two jockeys when they tag along with Mimi and Papa to the Kentucky Derby in Louisville, Kentucky.

"It was the 100th anniversary of the founding of the Pennsylvania town of Hershey-home of the world-famous Hershey Chocolate Factory! Christina, Grant, Mimi and Papa visit the Sweetest Place on Earth one cold February week to do research for Mimi's new mystery book. The kids and their new friends, Annabelle and Sean, quickly become involved in a curious mystery that involves stolen silver dollars... Learn about Milton Hershey, once child candymaker...

"Grant and Christina can't wait to visit Colonial Williamsburg with their mystery-writing grandmother Mimi and cowboy-pilot grandfather Papa. 'It feels like you are whisked back in time when you go to Williamsburg!' says Mimi. And as soon as the kids arrive, they're whisked into a quirky colonial mystery involving a valuable--and missing--map! It's a gift for the Queen of England--but where is it? Join Grant and Chrstina as they tour some taverns,...

Siblings Grant and Christina journey with their grandparents, Mimi and Papa, to Charleston, South Carolina, to search for their long lost Aunt Lulu and learn about the Civil War at Fort Sumter, but uncover a mystery involving a rare winter blizzard.

Siblings Grant and Christina visit Yellowstone National Park with their grandparents, Mimi and Papa, where they examine bubbling mud pots, geysers, and a volcano; and uncover a mystery.