Rolfe remained watching the house for some time, but no sign or sound of life could he detect in its silent desolation.  “I must have been mistaken,” he muttered, with a final glance at the windows of the first story.  “There’s nobody in the house.”

He turned to go, and had taken a few steps through the pinewood when suddenly he started and stood still.  His quick ear had caught a faint sound—­a kind of rattle—­coming from the direction of the house.  What was that noise which sounded so strangely familiar to his ears?  He had it!  It was the fall of a Venetian blind.  Instantaneously there came to Rolfe the remembrance that Inspector Chippenfield had ordered the library blind to be left up, so that when the sun was high in the heavens its rays, striking in through the window over the top of the chestnut-tree, might dry up the stain of blood on the floor, which washing had failed to efface.  Somebody was in the library and had dropped the blind.

Rolfe hurriedly retraced his steps to the edge of the plantation, and raced across the Italian garden, feeling for his revolver as he ran.  Some instinct told him that he would find entrance through the French windows on the west side of the morning room, and thither he directed his steps.  He pulled out his electric torch and tried the windows.  They were shut, and the first one was locked.  The second one yielded to his hand.  He pulled it open, and stepped into the room.  Making his way by the light of his torch to the stairs, he swiftly but silently crept up them and turned to the library on the left of the first landing.  The door was closed but not locked, and a faint light came through the keyhole.  Rolfe pushed the door open, and looked into the room.  A man was leaning over the dead judge’s writing-desk, examining its contents by the light of a candle which he had set down on the desk.  He was so engrossed in his occupation that he did not hear the door open.

“What are you doing there?” demanded Rolfe sternly.  His voice sounded hollow and menacing as it reverberated through the room.

The man at the desk started up, and turned round.  It was Hill.  When he saw Rolfe he looked as though he would fall.  He made as if to step forward.  Then he stood quite still, looking at the officer with ashen face.

“Hill,” said Rolfe quietly, “what does this mean?”

The butler had regained his self-composure with wonderful quickness.  The mask of reticence dropped over his face again, and it was in the smooth deferential tones of a well-trained servant that he replied: 

“Nothing, sir, I just slipped over from the shop to see if everything was all right.”

“How did you get into the house?”

“By the French window, sir.  I had a duplicate key which Sir Horace had made.”

“And I see you also have a duplicate key of the desk.  Why didn’t you give these keys up with the others to Inspector Chippenfield?”