Sam, Derek, and Caitlin love solving mysteries, and when they visit Washington, DC, spies are lurking. What starts out as a fun game of pretend on the National Mall turns all too real when they follow a mysterious man to a meeting deep within the Capitol. To keep government secrets from falling into the wrong hands, the kids must work with federal agents and travel to historic Mount Vernon for a state dinner with the president and his son.

Sam, Derek, and Caitlin can't believe their luck when they are invited by Professor Evanshade to help with the archaeological digs for a week at Jamestown's Field School. Maybe they'll uncover something spectacular tracing all the way back to Captain John Smith and Pocahontas! But when one of the priceless artifacts dug from the Jamestown Fort is labeled a fraud, it threatens to upend the entire archaeological project. Can the kids expose the secret conspiracy, or have they finally gotten in over their heads?

Sam, Derek, and Caitlin have encountered many mysteries together, but when they visit Maymont, Richmond's historic estate, danger is lurking at every turn. A chance meeting with a mysterious stranger leads to a frantic chase and a desperate message to save Maymont's bald eagles. When Sam receives an eerie warning in the middle of the night, Derek and Caitlin devise a plan that leads them high into the Blue Ridge Mountains. To save the eagles, the kids must find a secret abandoned palace, survive the wilds of the Appalachian Trail, and avoid capture by criminals, all before midnight.

Something's lurking beneath the famous staircase at The Jefferson. Back in 1895, when the hotel opened, real alligators roamed free in the courtyard fountains. That was ages ago... or was it? When young brothers Sam and Derek arrive at The Jefferson for an elegant wedding weekend with their parents, they love exploring the old hotel. But when the wedding rings go missing and Sam is blamed, the boys and their friends must hunt down the truth no matter where it leads.

Legend says that the haunting lights over the rapids on the James River at night are the ghosts of long-dead soldiers still fighting the Civil War. Just past the water lies historic Belle Isle, the former Union soldier prisoner-of-war camp, now a city park filled with crumbling ruins and dark wooded trails. When brothers Sam and Derek explore the island and local monuments to Richmond's past on the 150th anniversary of the Civil War with their friend Caitlin, some ghosts may be more alive than they expected!

In 1959, the Prince Edward County, Virginia, public schools closed. For five years. Back then, it wasn’t over a health pandemic, but because county leaders refused to desegregate white and Black schools. So when long-hidden photographs surface from the student protests along Main Street in Farmville, Sam, Derek, and Caitlin are on the case to help identify the brave teenagers who stood for justice nearly 60 years ago. 

When 10-year-old Derek and 8-year-old Sam move with their family to Virginia, they have no idea what adventures the summer will bring. As the brothers explore their creaky old house and the deep surrounding woods, they uncover a 60-year-old mystery of a valuable coin collection stolen from the local museum.

When Stella and her younger brother, Tom, move to their new London home, they become mystified by the disappearances of Harry, their elderly neighbor's small dog. Where does he go? And why does he keep reappearing wet-through? Their quest to solve the riddle over the summer holidays leads to a boat buried under a grassy mound, and a tunnel that takes them to a secret lake. 

When Zet's father left home to fight the Hyksos, his only option was to leave siblings Zet and Kat in charge. It turns out keeping food on the table is easier said than done. They need a solution and they need it now. One day, Zet spots a thief running through their market square. When the thief gets away, the medjay announce a reward for the man's capture. Zet jumps at the chance. The medjay, however, laugh at him. Zet cares little what they think. The siblings soon set off on a dangerous investigation.

ARE YOU A GIFTED CHILD LOOKING FOR SPECIAL OPPORTUNITIES? Dozens of children respond to this peculiar ad in the newspaper and are then put through a series of mind-bending tests. (And you, dear listener, can test your wits right alongside them.) Only four children - Reynie, Kate, Sticky, and Constance - succeed. Their challenge: to go on a secret mission that only the most intelligent and inventive children could complete.