Teenage detectives Frank and Joe Hardy investigate a supposedly haunted house reported to be the hangout of criminals.

A hard-bitten former search-and-rescue dog helps solve a complicated missing chicken case.

In two separate cases Joe and Frank Hardy search for stolen jewels to prove a man's innocence and attempt to catch a gang of drug smugglers

Relates the exploits of the four Alden children as they locate a missing man.

"With a knack for trivia, Encyclopedia solves mysteries for the neighborhood kids through his detective agency. But his Dad is also the chief of police, and every night, Encyclopedia helps him solve his most baffling crimes. Join Encyclopedia Brown as he solves ten confounding mysteries, including a case of a kidnapped millionaire, a dangerous dog and his mean owner, a famous big-town crook, and more. And with the clues given in each case, readers...

The solutions to ten mysteries solved by Leroy "Encyclopedia" Brown are given in a separate section challenging the reader to match wits with the ten-year-old mastermind of Idaville's war on crime.

Idaville's secret weapon against lawbreakers, ten-year-old Encyclopedia Brown, assists the police force with ten insoluble cases. Solutions are at the back of the book.

"When a hunting accident claims a boy's life, his best friends all come under suspicion"--

The Boxcar Children investigate a mysterious ghost with a glowing pumpkin head at a friend's farm.