But it was his ally; Jim pointed to the lift with a grin. "Everybody else is in, sir," he said. "Just step in there an' I'll take you to the next floor. We'll switch off the light inside, but leave it on here as usual. Then we can see a mouse comin' up the stairs if need be, an' there's no other way in, unless a real ghost turns up." They took up their position, leaving the door of the lift open. Thus they could step out without noise if necessary. They had not long to wait. Scarcely five minutes had elapsed before the porter, with an ear trained to the noises of the building, whispered eagerly: "Some one has just closed the front door, sir." They heard ascending footsteps. It was Van Hupfeldt, panting, darting quick glances at shadows, hastening up the stairs with a sort of felon fright. In front of No. 7 he paused and listened. Apparently not daring to risk everything, he rang the bell; he had not forgotten that a bullet had seared his leg at one of his unauthorized visits. Again he listened, being evidently ready for flight if he heard any answering sound. Then, finding all safe, he produced a key, entered, and closed the door behind him. "Well, I'm--" began the porter, in a tense whisper, this unlawful entry being a sacrilege to him. But David said in his ear: "Let him alone; we have him bottled." Nevertheless, seeing that Violet had undoubtedly stated her intent (or it seemed like that) to visit the flat that night, he began to consider what he should do if she put in an appearance. What would happen if she unexpectedly encountered Van Hupfeldt within? That must be provided for. The unforeseen difficulty was an instance of the poverty of man's judgment where the future is concerned. In keeping his implied promise to Violet, he would expose her to grave peril; for, in David's view, Van Hupfeldt had done her sister to death in that same place, and there was no knowing what the crime a man in desperate straits would commit. David was sure now that, actuated by widely different motives, both Van Hupfeldt and Violet were bent on searching for the photograph and letter reposing securely in his own pocket. He smiled grimly as he thought of that which Van Hupfeldt would find, but, obviously, he ought to warn Violet beforehand. Or would it suffice if he followed quickly after her, thus giving her the opportunity of scaring Van Hupfeldt into the right mood to confess everything? There was a slight risk in that; but it seemed to offer the best solution of a difficulty, and it would avoid the semblance of collusion between them, which Van Hupfeldt was adroit enough to take advantage of. So, when Violet did run lightly up the stairs, though his heart beat with joy at the sight of her, he restrained himself until she had opened the door. She applied her key without hesitation. "She trusts in me fully, then!" thought David, with a pang of regret that he should be compelled now to disobey her.