When a gang that uses parties as a cover for robberies victimizes a masquerade party Nancy is attending, the teen-age detective switches identity with her girl friend to solve the case.

"Agrand treasure for fans of the grande dame of mystery, The harlequin tea set and other stories brings together nine rare and brilliant Christie tales of murder and detection that span nearly half a century of her storytelling genius."--Publisher description.

In their latest case, animal detectives Bunny and Jack help Mabel the duck find out who stole the sugar cubes from her tea room.

Ruth Rose, Josh, and Dink attend a concert during which someone steals the star's diamond pendant, and they are soon on the trail of the thief.

A fifth-grader with a photographic memory and her friend Eric help solve the mystery of the stolen diamonds.

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.

While learning detective skills at a sleep-away camp, Dink and his friends undercover a real mystery involving stolen paintings.

In spite of a phony clue and trouble from a fierce cat, Nate the Great is able to use his skills of detection to find the remaining parts of an incomplete message left mysteriously on his doorstep.

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

The town's ten-year-old walking encyclopedia again solves ten neighborhood mysteries. The final solutions to the cases are at the back of the book, giving the reader a chance to compare his skill to that of Encyclopedia Brown.