The Mystery of the Invisible Thief

Who is the mysterious robber that disappears from the scene of the crime without a trace? What does the strange criss-cross pattern on the ground mean? Can the Five Find-Outers and Dog discover the thief's identity before Mr Goon does?

The eighth book in the series is a nice whodunit and howdedoit that keeps you guessing all the way through. It's pretty clever. The thief of the title breaks into houses and steals a few valuables before vanishing into thin air. No one sees him come or go. It's as if he's invisible! And this thief is so sure of himself that he leaves his big footprints and gloveprints everywhere—together with a curious round indentation with a criss-cross pattern in the dirt. And then there are a couple of other weird clues that just don't seem to fit anywhere...