Idaville's secret weapon against lawbreakers, ten-year-old Leroy "Encyclopedia" Brown, helps the police force solve ten new cases, the solutions to which are found in the back of the book.

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.

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.