Where was the motive for the crime? Until that was made clear I could not hope to piece together the scraps of evidence into a solid structure of proof. And what motive could there be that would reconcile the Doddridge Knapp who sought the life of Henry Wilton, with the Doddridge Knapp of this morning, who was ready to engage him in his confidential business? And had I the right to accept any part in his business? It had the flavor of treachery about it; yet it seemed the only possible chance to come upon the secret springs of his acts, to come in touch with the tools and accomplices in his crime. And the unknown mission, that had brought Henry to his death? How was I to play his part in that? And even if I could take his place, how was I to serve the mysterious employer and Doddridge Knapp at the same time, when Doddridge Knapp was ready to murder me to gain the Unknown's secret. Fatigue and loss of sleep deepened the dejection of mind that oppressed me with these insistent questions, and as I vainly struggled against it, carried me at last into the oblivion of dreamless slumber. The next I knew I was awaking to the sound of breaking glass. It was dark but for a feeble light that came from the window. Every bone in my body ached from the cramped position in which I had slept, and it seemed an age before I could rouse myself to act. It was, however, but a second before I was on my feet, revolver in hand, with the desk between me and a possible assailant. Silence, threatening, oppressive, surrounded me as I stood listening, watching, for the next move. Then I heard a low chuckle, as of some one struggling to restrain his laughter; and so far from sympathizing with his mirth, I was tempted to try the effect of a shot as an assistance in suppressing it. “I thought the transom was open,” said a low voice, which still seemed to be struggling with suppressed laughter. “I guess it woke him up,” said another and harsher voice. “I heard a noise in there.” “You're certain he's there?” asked the first voice with another chuckle. “Sure, Dicky. I saw him go in, and Porter and I have taken turns on watch ever since.” “Well, it's time he came out,” said Dicky. “He can't be asleep after that racket. Say!” he called, “Harry! What's the matter with you? If you're dead let us know.” They appeared friendly, but I hesitated in framing an answer. “We'll have to break down the door, I guess,” said Dicky. “Something must have happened.” And a resounding kick shook the panel. “Hold on!” I cried. “What's wanted?” “Oh,” said Dicky sarcastically. “You've come to life again, have you.” “Well, I'm not dead yet.” “Then strike a light and let us in. And take a look at that reminder you'll find wrapped around the rock I heaved through the transom. I thought it was open.” And Dicky went off into another series of chuckles in appreciation of his mistake.