When a mysterious person called the Fox begins to threaten young starlets, Lulu Dark investigates, even though she suspects that her own mother--an aging actress--might be behind it all.

When someone steals her purse and her identity, high-school junior and reluctant girl sleuth ("don't call me Nancy Drew!") Lulu Dark investigates.

As she tries to stay alive after being left on an iceberg in the Antarctic, sixteen-year-old Vicky recalls the series of events that brought her to the bottom of the world and involved her in a dangerous mystery.

Connor is sure his best friend, Branwell, couldn't have hurt Branwell's baby half sister, Nikki. But Nikki lies in a coma, and Branwell is in a juvenile behavioral center, suspected of a horrible crime and unable to utter the words to tell what really happened. Connor is the only one who might be able to break through Branwell's wall of silence. But how can he prove Branwell didn't commit the unspeakable act of which he's accused - when Branwell can't speak for himself?

Fourteen-year-old Nick and his bumbling detective brother Tim Diamond investigate a mystery involving international spies and assassins.

After his older brother, a fledgling private detective, agrees to safeguard a package for a dwarf who does not live long, thirteen-year-old Nick scampers to solve the mystery while also trying to stay one step ahead of an assortment of thugs.

A collection of three Diamond Brothers mysteries in which Tim and Nick bungle their way through a search for a missing philanthropist, find themselves in a Parisian prison, and are stranded on a Scottish island with a murderer.

When thirteen-year-old Nick is framed for a jewel robbery, he and his brother, the bumbling detective Tim Diamond, attempt to clear his name by capturing the master criminal known as the Fence.

In eighteenth-century Japan, young Seikei becomes involved with a ninja as he helps Judge Ooka, his foster father, investigate the murder of a samurai.

In eighteenth-century Japan, fourteen-year-old Seikei, a merchant's son in training to be a samurai, helps his patron investigate a series of murders and arson in the capital city of Edo, each of which is associated in some way with a popular geisha.