"That does not render the discovery less bitter," Mrs. Rent said sadly. "But I am sure that is not all. There is something worse behind. And if you will tell me what it is——"
"I cannot," Charlock said, "because I do not know. But you will need all your courage and strength before long."
CHAPTER XXXVIII
THE EMPTY ROOM
Malcolm Grey sat himself down to wait grimly and patiently for Tanza. From his position on the lawn he commanded a view of the front of the house. He had the satisfaction of knowing that Rent was safe and that he could not leave without being seen. In one of the rooms at the top of the house the light flickered from time to time, so that Grey had a fair idea of where Rent was and what he was doing. The better part of half an hour elapsed before Tanza appeared on the scene. Grey hailed him in a whisper, and he crept noiselessly across the grass. For once he appeared to be curious.
"What is on foot now?" he demanded. "Why did you send for me in so mysterious a fashion? Why is there a light at the top of the house? Is the problem solved?"
"To all practical purposes it is," Grey replied. "I know what took place, and why. But precisely how the mischief was brought about I cannot say. Possibly before daylight the thing may be explained. But that depends upon luck. At any rate, I am going to take you into my confidence and tell you what I have discovered."
"I am glad to hear that," Tanza murmured.
Tanza inclined his head to listen, and for the next quarter of an hour followed Grey with the most careful attention. He was more interested than perhaps he had ever been before in his life. The strangely tangled web which Grey was unfolding was the most complicated of all the affairs in which he had ever been engaged.
"Wonderful," he murmured. "Really, a work of art. Perhaps it is rather cold-blooded of me to regard these puzzles in the way of a recreation. But there is a peculiar horror about this affair which has rarely been equalled. So that's the way the thing was done, eh? Well, I suppose I must leave the matter in your hands. What do you propose to do next? But, by the way, you have not yet told me who is in the bedroom overhead."