In 1878 in London, Sally, now twenty-two and established in her own business, and her companions Frederick and Jim try to solve the mystery surrounding the unexpected collapse of a shipping firm and its ties to a sinister corporation called North Star. The year is 1878 and Sally Lockhart has just started her own financial consulting business when one of her clients loses a fortune in the unexpected collapse of a British shipping firm. As she struggles...

In an attempt to understand why her best friend committed suicide, eighteen-year-old Cody Reynolds retraces her dead friend's footsteps and makes some startling discoveries.

Danny Dragonbreath and his friends try to help the senior reptiles of Sunny Acres find a lost item.

When Ted and Kat's cousin Salim disappears from the London Eye ferris wheel, the two siblings must work together--Ted with his brain that is "wired differently" and impatient Kat--to try to solve the mystery of what happened to Salim.

Thirteen-year-old Ruby, a genius code-cracker and daring detective, gets an anonymous call setting a challenge that leads her to the headquarters of Spectrum, a highly secret anti-crime agency that needs her help to crack a code, but soon Ruby uncovers dastardly plans of the Fool's Gold Gang.

A young detective is determined to uncover which of the Santas he sees in the big city is the one and only Santa Claus.

In 1867, Sherlock Holmes, an impoverished young outcast with a Jewish father and a highborn mother, visits the scene of a woman's brutal murder, where he meets a wrongly accused young Arab and becomes a suspect himself.

The Alden siblings continue their mission to return lost artifacts around the world by visiting the Great Wall of China and an elephant reserve in Thailand, among other sites, but halfway around the world trouble seems closer than ever.

On a whale watch, Meg tries to solve a puzzling case involving a stolen treasure map. The reader is asked to solve the mystery before Meg, using clues found in the text and illustrations.