As they continue their search for the 39 Clues in China, fourteen-year-old Amy is faced with a terrible dilemma when her eleven-year-old brother Dan suddenly disappears--keep on searching for the next Clue or try to find her brother.

The first book in the #1 bestselling phenomenon sends readers around the world on the hunt for the 39 Clues! Minutes before she died Grace Cahill changed her will, leaving her descendants an impossible decision: "You have a choice - one million dollars or a clue." Grace is the last matriarch of the Cahills, the world's most powerful family. Everyone from Napoleon to Houdini is related to the Cahills, yet the source of the family power is lost. 39...

Amy and Dan travel to a distant land to follow in the footsteps of their most formidable ancestor yet, a military leader who teaches them the art of ancient warfare.

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....

Amy and Dan Cahill have their final confrontation with twisted billionaire J. Rutherford Pierce, a man whose power has no limits and is one step away from being elected president.

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.

"Why would Quentin Herms flee into the Quag? There was nothing in the Quag except certain death. Vega Jane has never left the village of Wormwood. But this isn't unusual--nobody has ever left the village of Wormwood. At least not until Quentin Herms vanishes into the unknown. Vega knows Quentin didn't just leave--he was chased. And he's left behind a very dangerous trail of clues that only she can decode. The Quag is a dark forest filled with terrifying...

Ruby Redfort is a genius code-cracker, a daring detective, and a gadget-laden special agent who just happens to be a 13-year-old girl. She and her slick side-kick butler, Hitch, foil crimes and get into loads of scrapes with evil villains, but they're always ice-cool in a crisis.

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.

"Fourteen-year-old Amy Cahill and her younger brother, Dan, head to the Land Down Under to discover what their own mother and father knew about the hunt for the 39 Clues, but following in their parents' footsteps brings up lost memories for Amy so awful that she can't share them, even with Dan. Haunted by the ghosts of their past, chased by deadly competitors, Dan and Amy can't see who is an enemy and who is a friend. Their blindness leads to a terrible...