"No time shall be lost," replied my friend, quietly. "May I request you to accompany Detective-Inspector Wess.e.x and Mr. Knox to the Guest House by the high road? Do not needlessly alarm Mrs. Camber. Indeed, I think you might confine your attention to Mrs. Powis. Merely request permission to walk down the garden to the hut, and be good enough to wait there until I join you, which will be in a few minutes after your arrival."

Inspector Aylesbury uttered an inarticulate, grunting sound, but I, who knew Harley so well, could see that he felt himself to be upon the eve of a signal triumph. What he proposed to do, I had no idea, save that it was designed to clear Colin Camber. I prayed that it might also clear his pathetic girl-wife; and in a sort of gloomy silence I set out with Wess.e.x and Aylesbury, down the drive, past the lodge, which seemed to be deserted to-night, and along the tree-lined high road, cool and sweet in the dusk of evening.

Aylesbury was very morose, and Wess.e.x, who had lighted his pipe, did not seem to be in a talkative mood either. He had the utmost faith in Paul Harley, but it was evident enough that he was oppressed by the weight of evidence against Camber. I divined the fact that he was turning over in his mind the idea of the frame-up, and endeavouring to re-adjust the established facts in accordance with this new point of view.

We were admitted to the Guest House by Mrs. Powis, a cheery old soul; one of those born optimists whose special task in life seems to be that of a friend in need.

As she opened the door, she smiled, shook her head, and raised her finger to her lips.

"Be as quiet as you can, sir," she said. "I have got her to sleep."

She spoke of Mrs. Camber as one refers to a child, and, quite understanding her anxiety:

"There will be no occasion to disturb her, Mrs. Powis," I replied. "We merely wish to walk down to the bottom of the garden to make a few enquiries."

"Yes, gentlemen," she whispered, quietly closing the door as we all entered the hall.

She led us through the rear portion of the house, and past the quarters of Ah Tsong into that neglected garden which I remembered so well.

"There you are, sir, and may Heaven help you to find the truth."

"Rest a.s.sured that the truth will be found, Mrs. Powis," I answered.

Inspector Aylesbury cleared his throat, but Wess.e.x, puffing at his pipe, made no remark whatever until we were all come to the hut overhanging the little ravine.

"This is where I found the rifle, Detective-Inspector," explained Aylesbury.

Wess.e.x nodded absently.

It was another perfect night, with only a faint tracery of cloud to be seen like lingering smoke over on the western horizon. Everything seemed very still, so that although we were several miles from the railway line, when presently a train sped on its way one might have supposed, from the apparent nearness of the sound, that the track was no farther off than the grounds of Cray's Folly.

Toward those grounds, automatically, our glances were drawn; and we stood there staring down at the ghostly map of the gardens, and all wondering, no doubt, what Harley was doing and when he would be joining us.

Very faintly I could hear the water of the little stream bubbling beneath us. Then, just as this awkward silence was becoming intolerable, there came a sc.r.a.ping and scratching from the shadows of the gully, and:

"Give me a hand, Knox!" cried the voice of Harley from below. "I want to avoid the barbed wire if possible."

He had come across country, and as I scrambled down the slope to meet him I could not help wondering with what object he had sent us ahead by the high road. Presently, when he came clambering up into the garden, this in a measure was explained, for:

"You are all wondering," he began, rapidly, "what I am up to, no doubt. Let me endeavour to make it clear. In order that my test should be conclusive, and in no way influenced by pre-knowledge of certain arrangements which I had made, I sent you on ahead of me. Not wishing to waste time, I followed by the shorter route. And now, gentlemen, let us begin."

"Good," muttered Inspector Aylesbury.

"But first of all," continued Harley, "I wish each one of you in turn to look out of the window of the hut, and down into the Tudor garden of Cray's Folly. Will you begin, Wess.e.x?"

Wess.e.x, taking his pipe out of his mouth, and staring hard at the speaker, nodded, entered the hut, and kneeling on the wooden seat, looked out of the window.

"Open the panes," said Harley, "so that you have a perfectly clear view."

Wess.e.x slid the panes open and stared intently down into the valley.

"Do you see anything unusual in the garden?"

"Nothing," he reported.

"And now, Inspector Aylesbury."

Inspector Aylesbury stamped noisily across the little hut, and peered out, briefly.

"I can see the garden," he said.

"Can you see the sun-dial?"

"Quite clearly."

"Good. And now you, Knox."

I followed, filled with astonishment.

"Do you see the sun-dial?" asked Harley, again.

"Quite clearly."

"And beyond it?"

"Yes, I can see beyond it. I can even see its shadow lying like a black band on the path."

"And you can see the yew trees?"

"Of course."

"But nothing else? Nothing unusual?"

"Nothing."

"Very well," said Harley, tersely. "And now, gentlemen, we take to the rough ground, proceeding due east. Will you be good enough to follow?"

Walking around the hut he found an opening in the hedge, and scrambled down into the place where rank gra.s.s grew and through which he and I on a previous occasion had made our way to the high road. To-night, however, he did not turn toward the high road, but proceeded along the crest of the hill.

I followed him, excited by the novelty of the proceedings. Wess.e.x, very silent, came behind me, and Inspector Aylesbury, swearing under his breath, waded through the long gra.s.s at the rear.

"Will you all turn your attention to the garden again, please?" cried Harley.

We all paused, looking to the right.

"Anything unusual?"

We were agreed that there was not.

"Very well," said my friend. "You will kindly note that from this point onward the formation of the ground prevents our obtaining any other view of Cray's Folly or its gardens until we reach the path to the valley, or turn on to the high road. From a point on the latter the tower may be seen but that is all. The first part of my experiment is concluded, gentlemen. We will now return."