Someone stole 'Old Rusty,' Ralphie Jordan's trusty bicycle. Jigsaw and Mila hit the trail to track down the thief. But one piece of the puzzle doesn't fit. Who would take a hand-me-down bike? Solving this case is an uphill ride for ace detectives Jigsaw and Mila.

Cam and her friend Eric chase the thief of Aunt Katie's wallet through an amusement park and find themselves involved in another case requiring their special detective skills.

While trying to recover a set of stolen parchment paintings, Nancy Drew becomes involved in tracking a kidnapper and extortionist.

When Cam Jansen and her friend Eric uncover a mystery while selling fudge door-to-door to raise money for the local library, Cam uses her photographic memory to foil a crime.

The gift of an oriental rug with a coded message woven into its border and the disappearance of a Turkish client start Nancy Drew on a new search for a missing mannequin.

Nancy Drew and her two friends help uncover a gang of swindlers while vacationing in a seaside town.

Ten brief cases allow the reader to match wits with ten-year-old crime-buster, Encyclopedia Brown, as he investigates such cases as whether a diary of George Washington's mother is authentic, or if a UFO picture supposedly taken by the army is real.

When the quarters which Arthur has collected for Mrs. MacGrady's charity drive disappear, Buster attempts to solve the mystery and prove his friend's innocence.

A chance meeting with a stranger on the road provides the Hardy brothers with a clue to a gang of local burglars.

When she notices some bones missing from a dinosaur skeleton exhibited in the museum, a young girl with a photographic memory tries to discover who has been taking them and why.