“My God, she’s fainted!” he exclaimed.

“I haven’t,” Laura faltered, trying to open her eyes, “and I’m not going to, but I think my arm’s broken, and my side hurts.”

“The fellow’s not down here, anyway,” Quest declared.  “Let’s help her upstairs and get her out of this devil’s house.”

They supported her up the steps and found a chair for her in the hall.  She was white almost to the lips, but she struggled bravely to keep consciousness.

“Don’t you bother about me,” she begged.  “Don’t let that blackguard go!  You find him.  I shall be all right.”

The Inspector swung open the telephone cupboard and called for an ambulance.  Then Quest, who had been examining the staircase, suddenly gave a little exclamation.

“He’s done us!” he cried.  “Look here, French, this is the original staircase.  There’s the leather loop.  I know it because there was a crack on the fourth stair.  When we rushed down the cellar after him, he swung the thing round again and simply walked out of the front door.  Damn it, man, it’s open!”

They hurried outside.  French blew his whistle.  One of the plain-clothes men came running up from the avenue.  He was looking a little sheepish.

“What’s wrong?” French demanded.

“He’s gone off,” was the unwilling reply.  “I guess that chap’s given us the slip.”

“Speak up,” French insisted.

“The only place,” the man went on, “we hadn’t our eyes glued on, was the front door.  He must have come out through that.  There’s been a motor truck with one or two queer-looking chaps in it, at the corner of the avenue there for the last ten minutes.  I’d just made up my mind to stroll round and see what it was up to when Jim, who was on the other side, shouted out.  A man jumped up into it and they made off at once.”

“Could he have come from this house?” French asked sternly.

“I guess, if he’d come out from the front door, he might just have done it,” the man admitted.

Quest and the Inspector exchanged glances.

“He’s done us!” Quest muttered,—­“done us like a couple of greenhorns!”

The Inspector’s rubicund countenance was white with fury.  His head kept turning in the direction of Laura, to whom the Professor was busy rendering first aid.

“If I never take another job on as long as I live,” he declared, “I’ll have that fellow before I’m through!”

2.

The Professor roused himself from what had apparently been a very gloomy reverie.

“Well,” he announced, “I must go home.  It has been very kind of you, Mr. Quest, to keep me here for so long.”

Quest glanced at the clock.

“Don’t hurry, Mr. Ashleigh,” he said.  “We may get some news at any moment.  French has a dozen men out on the search and he has promised to ring me up immediately he hears anything.”

The Professor sighed.