But they had not been quite clever enough for Silva. He had been too suspicious to let an incident like that pass. He had appeared to bow to the inevitable, but, all the same, he had followed his unwelcome visitors, and probably discovered their secret. And the worst of it was, Silva was now quite prepared for the intruders. It was impossible, too, for Vera to warn her friends. She racked her brains for some way of giving them a signal. There was only one desperate step to take, and she decided to risk it. Back once more she went until she came at length to the landing on the first floor. Her idea was to find out where Silva was hiding. There was a strong smell of cigarette smoke in the house, which appeared to come from the ground floor. There was only one thing for it, and that was to descend to the hall. Under the morning-room door there was just a thin slit of light. It was here that the smell of cigarette smoke was the strongest. It was here, no doubt, that Silva was waiting for the fray. So far as Vera could judge the morning-room was on one side of the house, so that in all probability the light would not be seen, or perhaps there were some heavy curtains or drapery over the window. From his own lips Vera knew something of what Silva's plans were. He was going to wait there till he had his enemies trapped overhead. He probably would not move till the critical moment came.

It was a desperate idea, but there was nothing else for it. Vera crept up to the little sitting-room, and hastily dashed off a few words of warning which she hoped might fall into Walter's hands. She did not doubt for a moment that he would be one of the rescuers. It seemed to her that if she placed the note on the little table with the night-light behind it, and left the door open, it would be bound to attract Walter's attention. Then he would be prepared for the attack from below. There was practically no chance of Silva coming upstairs in the meantime, so that there was no reason why the little plot should fail. It was done at length, and then Vera again crept up the iron ladder to the side of the tank. But she did not return to her room. She knew that she was perfectly safe where she was. And, besides, at any moment her assistance might be of the greatest value. She stood there in the pitchy darkness, the leaden moments creeping on like so many hours.

Her ears were strained to catch the slightest sound; even the trickle of a water-tap sounded like pistol shots. A mouse behind the wainscot appeared to be making noise enough to wake the dead. Then, above the creeping silence, came a quick snap, which was like the breaking of wood. Vera's heart gave a great leap. It seemed to her that the attack was commencing in earnest.

A minute or two later and she fancied she could hear footsteps in the hall. But this she dismissed as mere fancy. She could hear the trees rustling outside as they swayed to a sudden breeze. She hoped the wind would not be strong enough to blow out her night-light. She wished now that she had closed the window. Then she jumped with a nervous start as a door banged like the thud of artillery. She heard a quick, sharp cry, and then the laboured breathing as if two men were locked in a struggle to the death.

[CHAPTER XXXVII.]

AN UNEXPECTED FRIEND.

Outside in the garden, under cover of the darkness, Ravenspur and his companion waited anxiously for a sign from Walter. The minutes crept slowly on. Still there was nothing to break the silence. A quarter of an hour passed, and at length Ravenspur began to feel decidedly anxious.

"I don't like it," he murmured; "I don't like it a bit. We have an exceedingly cunning scoundrel to deal with, and a bloodthirsty one into the bargain. That man would not stick at anything. I can't understand how it is that Walter doesn't open the door."

Venables made no reply. As a matter of fact, he was not a whit less anxious than Ravenspur. Still the minutes crept on, and still there was no sign from the interior of the house. Then at last came a faint, dull report, which might either have been the closing of a door, or the muffled echo of a pistol shot. Before Venables could reply he felt something damp and cold against his hand. His nerves were now at high tension. He jumped quickly back, and looked down. A great hound stood there waving his long tail from side to side and looking up into Ravenspur's face as if not altogether sure as to his presence being welcome.

"Call him off," Venables said excitedly. "The brute is dangerous. By Jove, what a fool I am! I thought at first that this was one of our friend Valdo's bodyguard, but I see now that it is your dog, Lord Ravenspur. I suppose he has managed to get away again."