There are a great many clever burglaries going on and it is suspected that members of the gang have their meeting place somewhere in Peterswood. The Five Find-Outers naturally determine to solve the mystery and they tumble into three other mysteries in the process.
Who is the old man on the seat? Who is Number Three? Where is the missing necklace? For once Mr Goon, the policeman, outwits Fatty one strange night at the Waxworks Hall. But it all ends up most unexpectedly with the children finally triumphant.
