The suggestion of tragedy brooding in the darkness held Lance back just for the moment. He was almost afraid to proceed lest he should find something even worse than he had expected. Then his hand fumbled along the wall with the switches, and the great room burst into a glow of light again.

The place was absolutely empty, save for the figure of Lord Ravenspur huddled up upon the Persian rug. He was absolutely still and silent. As far as Lance could see he had ceased to breathe.

Naturally enough the young man looked about him for a sign of the miscreant, but the studio contained no trace of his presence. The thing was puzzling to the last degree. There was no exit from the room beyond the door which Walter had broken down, and nobody could possibly have passed him that way. Besides, the switches were just inside the door, and the light had been turned on almost immediately. At any rate, there was nobody there now except the victim of the attack himself, and Walter feared that he was already past any explanation of the strange affair.

That would have to keep for the present. Walter bent over and raised Lord Ravenspur\'s head and shoulders. He was still alive, for his eyes were wide open, though no words came from his lips. At the same time he seemed to be struggling for speech which would not come. Then he raised a shaking arm and contrived to pull Walter\'s head down close to his lips. The words came at length in a faint whisper, a whisper so low, that Walter had the greatest difficulty in following it.

"Don\'t let anybody know. It is absolutely necessary that no one should know," Lord Ravenspur faltered. "If there is any alarm, I pray you go and allay it at once. Say that I had fallen asleep and was suffering from nightmare, Say I had a horrible dream. Say anything, so long as you respect my secret. Now go."

There was nothing to do but to obey this mysterious request. At the end of the corridor Vera was waiting with an anxious face. It was no nice thing to prevaricate, it would have to be done. Walter spoke as lightly as possible.

"There is no occasion for alarm," he said. "Lord Ravenspur says that he fell asleep and had a horrible nightmare. At any rate, he seems to be all right now. You had better go to bed. I am sorry that you should have been so much alarmed."

To Walter\'s great relief, Vera asked no further questions. She turned away obediently enough, and he hurried back to the studio. Lord Ravenspur still lay on the Persian rug, but with Walter\'s help he contrived to get into a chair. A little brandy brought some trace of colour to his face. He seemed more like himself again. "They heard nothing in the house?" he asked anxiously.

"Only Vera," Walter explained. "She was terribly frightened, but she believed what I told her, and she has gone up to her room. And now, perhaps, you will tell me the truth."

"Do you think I have not already done so?"

"My dear uncle, I am sure of it. I know it is possible for people to make the most hideous noises when they are suffering from nightmare, but this is quite another matter. You called aloud for help. You were in imminent danger of losing your life. Before I broke the door down I distinctly heard somebody give a low chuckle. Of course, you can make light of this in the morning. You can induce people to laugh at your absurd situation, but you cannot deceive me. I know there was someone in the room when I forced the door."

"Then where is he now, Walter?" Lord Ravenspur asked.

"Ah, that I cannot tell; but he was here right enough."

"He passed you in the corridor?"

"That he most certainly did not. Nobody came out that way."

A faint smile came to Lord Ravenspur\'s lips. He indicated the room with a wave of his hand.

"I see exactly what you mean," Walter said. "Of course, if you do not feel inclined to tell me the truth I cannot compel you to do so. But I have only to look at you, to see that you have lately been through a desperate struggle with someone who came here to take your life. You are absolutely exhausted with the severity of it. If I had my own way I would put the matter in the hands of the police."

"No, no," Ravenspur said vehemently. "If you have the slightest regard for me you will not venture to say a word to a soul. I want the whole thing to be forgotten. If I remain in my room all tomorrow under the plea of indisposition, I shall be all right the next day. You are to give me your word of honour that you will say nothing of what you have seen tonight."

"If you wish it so, certainly," Walter said reluctantly.

"My dear uncle, won\'t you trust me? I would do anything to help you. And besides, how are you going to guard against this happening again?

"A bloodthirsty ruffian who can enter a house and vanish in this mysterious fashion, is not likely to be put off, if he knows you are going to take no steps to guard yourself against a further attack. But what has become of him?"

"I haven\'t the slightest idea," Ravenspur said wearily. "I was sitting in my chair when the light suddenly went out and I heard the door locked. Then I had to fight for my life, and was nearly done for when I called out for assistance."

"And you saw nothing of him?" Walter asked.

"Nothing whatever," Ravenspur went on. "I could only feel him. And after that I recollect no more till you came."

"A most extraordinary thing," Walter said, somewhat impatiently. "Surely you have some idea as to who the man is. Surely he must be the same man who mistook Sir James Seton for yourself tonight."

No reply came from Lord Ravenspur. Evidently he desired to say no more. He seemed anxious to be alone. But Walter, angry and hurt, walked rapidly about the room seeking for a way whereby the late visitor had vanished. But he looked in vain. There was no possible means of exit other than the door, and the fireplace was too narrow to admit of anybody coming or going. As to the roof, it was of heavy stained glass, and as impregnable as the walls themselves. The mystery was maddening. And yet the one man who could have explained it all sat there silent, and moody, and tongue tied.

"Is there anything more that I can do for you before I go to bed?" Walter asked. "Are you sure I can\'t help you?"

"I am afraid not, my boy," Ravenspur said in a dull, mechanical way. "I know that you won\'t chatter about this thing. And, perhaps, a little later on, I shall be able to speak more plainly. I shall be glad if you will help me up the stairs and get me into bed. I have had a great shock tonight."

It seemed almost cruel to pursue the subject further, and Walter refrained from questions as he noticed the ghastly whiteness of his uncle\'s face. The latter was disposed of at length, and then Walter came downstairs again. He now had the house practically to himself. All desire for sleep had forsaken him. Besides that, it was no nice thought to reflect on the possibility of that ruffian being still on the premises. Walter had not the slightest doubt in his mind that the man had left the studio in some secret manner, and that he had come there through no ordinary channel. What was to prevent him returning again when the house was asleep and finishing his work? In itself, the fact of Lord Ravenspur possessing a bitter enemy was remarkable. And Lord Ravenspur\'s obstinate silence was more remarkable still. Walter had given his word to say nothing of these strange events, but that did not bind him from making inquiries on his own account.

He returned to the studio once more and made a thoroughly searching examination of the place. Was there some secret door which Lord Ravenspur used, and of which nobody knew anything? It had never occurred to Walter till that moment that his uncle might have turned-down pages in his life, but that conclusion was inevitable now. Still, though Walter spent the best part of an hour in his search, he had nothing to show for his pains. He was about to give up the thing in despair when a piece of yellow paper, lying by the side of the Persian rug where Lord Ravenspur had fallen, attracted his attention. It was a small, shabby sheet of paper, folded in four and printed from worn-out type, in fact, just the class of bill which is circulated amongst travelling circuses and shows of that kind. It was the last thing in the world that anyone would have looked for in the studio of so fastidious a man as Lord Ravenspur. Slowly and thoughtfully Walter unfolded and read the handbill. It was an advertisement of the nightly programme of the Imperial Palace Theatre. The name of the place sounded imposing enough, but the locality of Vauxhall Bridge Road somewhat detracted from the importance of it. So far as Walter could judge, the Imperial Palace Theatre was no more than a shady music hall giving two shows a night, and most of the names on the bill were absolutely unknown to fame. The star turn appeared to be one Valdo, who was announced as the flying man who had made such a sensation throughout the leading halls in Europe.

"I wonder if this is a clue," Walter murmured to himself. "At any rate, I should like to see this Valdo. I\'ll go down to the Imperial Palace tomorrow night and enquire for myself."

Walter folded up the shabby bill and placed it in his pocket, after which he went thoughtfully to bed.