There was an agitated knock at the door, and an instant afterwards Dr. Huxtable was in the room. In his hand he held a blue cricket-cap with a white chevron on the peak.
“At last we have a clue!” he cried. “Thank heaven! at last we are on the dear boy’s track! It is his cap.”
“Where was it found?”
“In the van of the gipsies who camped on the moor. They left on Tuesday. Today the police traced them down and examined their caravan. This was found.”
“How do they account for it?”
“They shuffled and lied—said that they found it on the moor on Tuesday morning. They know where he is, the rascals! Thank goodness, they are all safe under lock and key. Either the fear of the law or the Duke’s purse will certainly get out of them all that they know.”
“So far, so good,” said Holmes, when the doctor had at last left the room. “It at least bears out the theory that it is on the side of the Lower Gill Moor that we must hope for results. The police have really done nothing locally, save the arrest of these gipsies. Look here, Watson! There is a watercourse across the moor. You see it marked here in the map. In some parts it widens into a morass. This is particularly so in the region between Holdernesse Hall and the school. It is vain to look elsewhere for tracks in this dry weather, but at that point there is certainly a chance of some record being left. I will call you early tomorrow morning, and you and I will try if we can throw some little light upon the mystery.”