“Yes, often,” answered Chub. “He was the real thing, too. He caught more desperate criminals than Sherlock Holmes ever thought of! And he was great for disguising himself, too.”

“Oh, that’s it!” cried Harry. “I must have a disguise!”

“Wear your hair on top of your head,” suggested Roy laughingly.

“Put your shoes on the wrong feet,” added Chub.

“Never you mind,” said Harry with sparkling eyes. “I know what I shall do. You wait and see. But if you recognize me—if you penetrate my disguise, I mean, you mustn’t let on. You won’t, will you? Because it might spoil everything.”

“You may depend upon us,” replied Roy gravely.

“We ought to have a password,” Harry continued. “So when we meet each other we can communicate.”

“‘R-r-r-revenge!’” muttered Chub with a ferocious scowl. Harry clapped her hands.

“That’s it! That’s the password! ‘Revenge!’ Don’t forget it.”