Lavendale was stonily silent, yet when the momentarily raised curtain had fallen he gave a little gasp. It could have been no hallucination. The face, transfigured though it was, in a sense, by its air of furtiveness, was, without a doubt, the face of the girl who had been constantly in his thoughts for the last three weeks. He counted the windows carefully from the ground, noted the exact position of the room and passed his arm through his friend's. 'Come along, Reggie,' he said. 'Where to?' 'Don't ask any questions,' Lavendale begged. 'Just wait.' They left the hotel by an unfrequented way, Lavendale half a dozen paces ahead. Merrill ventured upon a mild protest. 'Look here, old chap,' he complained, 'you might tell me where we are off to?' Lavendale slackened his speed for a moment to explain. 'To that room,' he declared. 'Didn't you recognize the girl's face?' Merrill shook his head. 'I scarcely noticed it.' 'It was the girl whom we found unconscious, half poisoned by that fellow Hurn's diabolical invention,' Lavendale explained. 'She wasn't there by accident, either. I caught her listening in the Milan Grill-room when Hurn was talking to me, and the day after the inquest she disappeared.' Merrill laid a hand upon his friend's arm. 'Even if this is so, Lavendale,' he expostulated, 'she probably doesn't want us bothering over here. What are you going to say to her? Pretty sort of asses we shall look if we blunder in upon her like this.' Lavendale continued to climb the stairs. By this time they had reached the second landing. 'If you feel that way about it, Merrill,' he said, 'you can wait for me--or clear out altogether, if you like. I want to have a few words with this young lady, and I am going to have them.' Merrill sighed. 'I'll see you through it, Ambrose,' he grumbled. 'All the same, I'm not at all sure that we are not making fools of ourselves.' They mounted yet another flight. A crazy lift went lumbering past them up to the top of the building. Lavendale paused outside a door near the end of the passage. 'This should be the one,' he announced. He rang a bell. They could hear it pealing inside, but there was no response. Once more he pressed the button. This time it seemed to them both that its shrill summons was ringing through empty spaces. There was no sound of any movement within. The door of the next flat, however, opened. A tall, rather stout man, very untidily dressed, with pale, unwholesome face and a mass of ill-arranged hair, looked out. 'Sir,' he said, 'it is no use ringing that bell. The only purpose you serve is to disturb me at my labours. The flat is empty.' 'Are you quite sure about that?' Lavendale asked. 'Absolutely!' 'How was it, then, that I saw a face at one of the windows a quarter of an hour ago?' Lavendale demanded.