Leroy Brown, aka Encyclopedia Brown, is Idaville's ten-year-old star detective. With an uncanny knack for trivia, he solves mysteries for the neighborhood kids through his own detective agency.

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.

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.

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.

Ten mysteries for ten-year-old Encyclopedia Brown, his partner, Sally, and the reader to solve. Solutions are given at the back of the book.

The ten-year-old detective continues his war on crime in Idaville through ten more cases, for which the reader is invited to guess the solution before it is revealed.

More mysterious cases for "America's Sherlock Holmes in sneakers" to solve for the standard twenty-five-cent fee. Solutions are included at the back of the book.

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.