Presently with that same peculiar grunt he took out a pocket-flash and a knife. Opening the knife he pried the point into what looked by the aid of the flash like a harmless knot-hole just beneath the lowest shelf. (He was kneeling on the floor of the safe and Jenkins and I were stooping to watch him.) The next moment the knot-hole had swung aside, revealing to our astonished gaze a tiny key-hole!
The back of the safe was in reality a door!
Silently we watched as McKelvie fished out his keys and tried them in the lock but without success. Then he spoke to Jenkins. "Tell Mason to give you all of Mr. Darwin's keys, but don't let him come in here."
"Very well, sir."
When Jenkins returned with the keys McKelvie tried them in the lock, one after the other, but the door remained as securely locked as before.
"Strange," he said, looking annoyed. "You are sure you brought me all the keys?" he added abruptly.
"Yes, sir, even the ones he had in his pocket when he was shot, sir," responded Jenkins.
"Odd. I hate to break it open. It might be useful later on."
Jenkins, who had been peering intently at the key-hole over McKelvie's shoulder, spoke suddenly. "No need to smash it, sir. I still have my old tool kit and if I'm not mistaken I have a master key that will fit this lock."
"Off with you, then. Break all traffic laws if necessary. Only be back as soon as possible," cried McKelvie gayly, and I never saw the solemn Jenkins move so fast before.