Tony Baker arrives at school one day, only to find that somebody has hacked into the school’s computer system, using his library code. Then Tony’s mother gets a letter from the Town Hall saying she must pay £10,000 for repair work to her bookshop. The letter is signed ‘Charles Smith’, but Tony discovers that Charles Smith does not exist. Who is the mysterious hacker and who sent the letter? Tony is determined to find out, but how?...