“Hurrah!” said Bets. “We’ve got one for these hols, after all! How shall we solve it?”

“Well - it’s not our usual sort of mystery,” said Fatty thoughtfully. “I mean - in the ones before we have had Clues and Suspects to work on - this time all we’ve got is a fully furnished room at the top of an empty house. We don’t even know if there’s anything wrong about it. But it’s certainly queer and unusual enough for us to try and find out what’s behind it.”

“Ooooh, how lovely!” said Bets joyfully. “I did so want a mystery these hols. Especially as we’ve got so many good detective tricks.”

“Well, Pip, you certainly had a good afternoon,” said Larry. “Do take off that awful disguise now. I can’t bear to look at you. It’s the teeth that make you look so revolting.”

“I know,” said Pip, taking them out and going to a basin to rinse them and dry them. “They’re marvellous. Old Clear-Orf nearly had a fit when he saw them flashing at him again, after seeing them in the French boy’s mouth!”

The others laughed at the thought of Mr. Goon’s surprise. Fatty suddenly looked thoughtful.

“I only hope old Clear-Orf won’t go snooping round after us,” he said. “I know it was fun to make him think we were in the middle of a new mystery he knew nothing about - but now that we really have stumbled on to one, it will be sickening if he follows us around. It will cramp our style terribly.”

“Blow!” said Larry. “We shan’t be able to keep this mystery to ourselves if Clear-Orf sniffs it out. I must say it sounds a first-class one - I find myself asking all kinds of questions! Who uses the room? Why in an empty house? Does the owner know about it? When does the one who uses it come and go?”

“Yes - there are all sort of questions to answer,” said Fatty. “It’s going to be interesting - but difficult! I vote we try and get into the room.”

“On no!” said every one at once.