Lady Candling lives next door to Pip & Bets & owns some very expensive pedigree Siamese cats. When her most famous cat Dark Queen goes missing the gardener's help Luke seems the obvious suspect. Mr Goon & Mr Tupping Lady Candling's gardener are sure he's the culprit as he was digging by the cat house all alone when Dark Queen disappeared. The Five Find-Outers must solve the mystery to clear the name of their friend Luke. Strangely Dark Queen soon reappears dirty & tired but unhurt. & stranger still she disappears again a few days later once more when only Luke could have done it. Piecing together clues of pale paint turps & some wellington boots the Five Find-Outers prove once more with the help of Inspector Jenks not only that Luke is innocent but that Mr Tupping took Dark Queen & deliberately tried to frame Luke for the crime.