There are a great many clever bulgaries going on and it is suspected that members of the gang have their meeting place somewhere in Peterswood. The Five find-outers are natuarally determined 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 end up most unexpectedly with the children finally triumphant.