The next stop was at the office, dark with a Sabbath darkness; but not for long. Within the space of a few minutes after he came, every light switched on, the windows open wide, his coat dangling from a chair in the corner, Roberts was at work upon a small mountain of correspondence collected upon his desk, a mountain of which each unit was marked "personal" or "private." At almost the same time a waiter from a near-by _cafe_ entered with a tray of sandwiches and coffee. Thereafter he ate as he worked. An hour passed. The sandwiches disappeared entirely and the mountain grew slightly smaller. A second hour dragged by and the mountain suffered a second decline. For the first time Roberts halted and glanced at the clock. A moment later he took down the receiver from the 'phone on his desk and gave a number. "That you, Randall? Has Armstrong been at your place to-night? You haven't seen him at all to-day, then. No; nothing. Just wanted to know, that was all. Good-night." Another half-hour passed; then, without pausing in his work, Roberts pulled the buzzer lever for a messenger. When the latter appeared he scribbled a few lines on a sheet of paper, addressed an envelope, and gave it to the boy with half a dollar. "There's a mate to that coin waiting here for you if you can get me an answer within half an hour," he said. "You know the party, don't you?" "Sure. Yes, sir." "Follow up the trail, then. You've lost one minute of your thirty already." For the third time he returned to his work, halting only when the messenger in blue returned. "Can't deliver it, sir," explained the latter curtly. "I've been all over town and no one has seen him. Thank you, sir. Good-night." For several minutes this time Darley Roberts sat in his desk chair thinking, quite motionless. The clock on the wall recorded midnight and he compared the time with his watch to make certain of its accuracy. Once more he took down the telephone receiver. "This you, Elice?" he asked after a moment. "Can I be of service? Never mind, no need to explain. I understand. I'll be right up." In spite of the city speed limit the big red car made those twelve blocks intervening in sixty-four seconds flat. * * * * * "How did you ever know?"--infinite wonder, infinite relief as well in the tone. "Tell me that, please." "I didn't know, of course. I merely guessed. Has it been long?" Involuntarily the girl shuddered, then held herself steady with an effort. "Yes, since dinner. He came while we were eating; and father--" "I understand," preventingly. "Don't worry. It's all over with now. Did any one else see--any of the neighbors, I mean?" "I think not. It was after dark and--Oh, it's simply horrible! horrible!" "Yes," gently. "I appreciate that. Let's not speak about it. Your two roomers are both in?" The girl nodded. "They didn't suspect anything wrong either?"