I heard a metallic click as McKelvie snapped on the handcuffs, and I opened my eyes with a start as I realized by the snarl of rage that had come from the murderer's lips that we had caught the man as neatly as one traps a wild and dangerous animal.
McKelvie laughed as he slammed the door of the safe, and the three of us rose precipitately (Jones had wakened when the lamp went on), for we could make out the criminal's figure as he came rapidly toward us. When he stood within the circle of light, confronting the muzzle of Jones' gun, I looked into his face, then I gasped audibly.
The man before me was not Dick, but the lawyer—Cunningham!
"This is an outrage!" he exclaimed furiously. "What do you mean by putting such an indignity upon me?" and he glared at McKelvie.
McKelvie smiled in an exasperating manner. "I was expecting the criminal to come through that entrance, since he alone possesses a key to it. I saw a man appear and clapped on the bracelets. It happened to be you. How do you explain the circumstance?" he inquired politely.
"Very easily," retorted Cunningham coolly, recovering his poise, "I was going over a lot of old papers and came across a sealed envelope addressed to me in Darwin's hand. Wondering what it could portend I opened it. Inside I found a small key and the explanation of the secret of the entrance. Darwin also went on to say that he was taking me into his confidence in case anything should ever happen to him. Having a fondness for amateur detective work, like yourself, Mr. McKelvie," here he bowed ironically to McKelvie, "I decided to use the opportunity which fate had bestowed upon me to do a little investigating on my own account."
"Very ingenious, but it won't do," returned McKelvie, adding with a sarcastic inflection, "I suppose he also told you the six-letter combination that I used to lock the safe—after he was dead?"
Cunningham flushed and bit his lip, but before he could think of an appropriate retort, McKelvie had turned to Jones.
"You won't need to use that gun, Jones," he said with a twinkle. "Our prisoner is too valuable to shoot—as yet. Call in the others, please, and light the room as you pass the switch."
Jones pocketed his gun, and departed on his errand, lighting the study, as we had agreed to do, for the guidance of the men outside. In a second he was back again with Lee and Cora. As Cunningham's eyes rested on the girl, who had her arm around Lee and was helping him tenderly to a chair, the man's face darkened and his eyes blazed upon her.