King & Kayla hunt for Asia's missing gold ring.

Using their code-breaking skills, four middle-schoolers solve the mystery of the eccentric man who draws stick figures on his second-floor bedroom window.

"An enigmatic message leads the Code Busters on a treasure hunt on creepy Alcatraz Island, where they must use their problem-solving skills to unravel the mystery" -- Publisher.

Fifteen-year-old Matt and his new friend Robin search the globe to retrieve an ancient code--rumored to have brought down the ancient civilization of Atlantis--from the hands of a madman who is bent on destroying the modern world.

Thirteen-year-old Dan Cahill and his older sister, Amy, are the latest guardians of the Clues--thirty-nine ingredients in a serum that transforms whomever takes it into the most powerful person on earth. They think they've done everything right, but a tiny mistake leads to catastrophe. The serum is missing and Dan and Amy have to get it back and stop who stole it...before it's game over.

It started with a kidnapping. A shadowy organization known only as the Vespers snatched seven members of the Cahill family and demanded a series of bizarre ransoms from around the world. Thirteen-year-old Dan Cahill and his older sister Amy began a global treasure hunt, determined to bring back whatever Vesper One needed, so long as it kept the hostages safe. But when they deliver the last ransom, Amy and Dan discover Vesper One's terrifying endgame....

Geronimo Stilton and his sister Thea search for a secret map hidden beneath a famous painting and soon uncover some amazing clues.

"Are some secrets better left buried? As Amy and Dan track the next clue to a remote corner of the world, they make shocking discoveries about the source of the Cahills' power and the mystery of their parents' deaths. And as the threat of the mysterious Madrigals grows real, one of the clue-hunters makes the ultimate sacrifice. Amy and Dan have to decide how much they're willing to risk, and what they are fighting for. Can they avenge their parents...

It's no longer a game. The body count is rising. Shaken by recent events, Amy and Dan flee to a distant land and trace the footsteps of their most formidable ancestor yet: a military leader of mythic proportions. Yet just as the siblings begin to master the art of ancient warfare, they confront a dangerous enemy that can't be felled with a sword: the truth. With the stakes higher than ever, Amy and Dan uncover something so devastating it changes everything--the...

For 500 years, the Cahills have been the most powerful family in the world. For 500 years, they've protected the source of their power - the 39 Clues. And for 500 years, they've kept their secrets silent. Until now. This extraordinary stand-alone novel cracks open the Cahill vault to tell the story of the most coveted piece of artwork in the world, a masterpiece that has been the target of seven separate theft attempts: Jan van Eyck's altarpiece at...