Fletcher Moon is a detective. But he's no ordinary detective: he also happens to be a 12-year-old boy. Fletcher's mum and dad worry about his obsession with solving crimes, and his teachers laugh at him. But it's not until a series of mysterious crimes unfold at Fletcher's school that his problems really begin. Fletcher decides to flex his detecting muscles, and with the help of the notorious Red Sharkey - who's no stranger to the police himself - he is determined to solve his first real case. But Fletcher and his unlikely ally are in much greater danger than they bargained for.