It is a detective novel, whose heroes are youngsters. This is the first novel of a series. In this series, these heroes will encounter an assignment and solve it. To solve the case, they will undoubtedly face life risks. And as you know, life-threatening is a part of the detecting job. The other intention of these novels is to be interesting for teenagers or who are weaker in English, so that young readers may get used to reading and enjoy it and learn English in this way. Anyway, read and enjoy.