The Kumquat Legacy

Here's a book for young readers (ages 10 and up) who love mysteries and puzzles. A rich man offers 13-year-old Dave a chance to receive the Kumquat Legacy, a mysterious prize of immense value. To win the prize, Dave must solve a series of riddles. Unfortunately, Cyril, the rich man's despicable nephew, will use every dirty trick imaginable to solve them first and claim the prize for himself.