As an apprentice on a training mission to 1912 England, Dorrie takes a chance that could lead the Strongholders to the Lybrarians' fortress, Petrarch's library.

When Kelly loses a little boy to monsters who live under his bed during her first babysitting job, she learns about a secret society of babysitters who fight monsters.

When the original Star Spangled Banner is stolen, seventh-graders Anne, José, and Henry, all descendants of the Silver Jaguar Society, pursue suspects on airport carts and through baggage handling tunnels while stranded at a Washington, D.C., airport during a snowstorm.

As they return to Rosewood after the dramatic events of their first year, Lottie and Ellie are hoping for a peaceful term. But strange things are happening at Rosewood. Pupils are being poisoned. Is the threat of secret organisation Leviathan growing closer? Lottie and Ellie are determined to find the culprit; but danger could be closer than they think.

After saving a piskie's life, twelve-year-old Emily Snow finds herself in the middle of a centuries-old war between rival fairy factions and a secret society named The Invisible Order.

"Eva has never felt like she belonged ... not in her own family or with her friends in New York City, and certainly not at a fancy boarding school like Hardwick Preparatory Academy. So, when she is invited to join the Fives, an elite secret society, she jumps at the opportunity to finally be a part of something. But what if the Fives are about more than just having the best parties and receiving special privileges from the school? What if they are...

When sixteen-year-old Avery West learns her family is part of a powerful and dangerous secret society, and that her own life is in danger, she must follow a trail of clues across Europe.

"Back for their second year at Pennyroyal Academy, Evie and her friends must unravel a devious plot to bring down the academy"--

The Alden siblings continue their mission to return lost artifacts around the world to their rightful homes by visiting the Pyramids in Egypt and Stonehenge in England, among other places, while outwitting a thief along the way.

When the guardians of the Copernicus legacy are targeted for assassination by the evil Galina Krause, Wade, Darrell, Lily, and Becca must find the remaining relics to defeat their enemies.