The secret to instant height? Stand on a box. Want to make your money go further? Roll it down a hill. The answer to smelly feet? Wear a clothes pin on your nose. Eleven-year-old Johnny Swanson is in business. He's raking in the money with his advertising scams and his advice columnist persona, who offers advice on absolutely anything in return for a shilling. But his money-making schemes are getting him in too deep with the wrong kinds of people. Everything is spiralling out of control, and now his own mother is in mortal danger. There's only one thing to be done: Johnny must assume another role as undercover detective! In the spirit of Roald Dahl, this is a funny and delightful story with a satisfying mystery, a wonderful cast of characters, and an unlikely but completely likeable hero.