"You're better qualified for the part of Mad Hatter, I fancy. Come, let's step it out."
The evening of that day turned out rather cool and overcast. A breeze sprang up in the south-west, refreshing after the still heat. After early supper, Armstrong, declaring that he was getting flabby for want of exercise, set off in the dinghy for a pull down the river. Pratt thought it a good opportunity for testing Armstrong's report of the sounds he had heard in the cottage, and went off alone, leaving Warrender on guard at the camp.
He had not yet come within sight of the ruins when, above the rustle of the stirred leaves, a strange moaning broke upon his ear. He stopped to listen. While far more impressionable than Armstrong, he had solid musical knowledge which his schoolfellow lacked, and he was struck at once by an unusual quality in the sound he heard.
"That's not the wind in the eaves," he thought. "It's more like the whining of an organ pipe when a lazy blower is letting the wind out."
He hurried on. The sound rose and fell. For some moments it maintained a steady, pure organ note; then with rising pitch it became almost a shriek.
"I don't wonder the rustics are a bit scared," he thought, "but no ghost could produce a tone like that--unless he'd been a cathedral alto in his lifetime. It's due, I expect, to some metal chimney-pot that's got displaced and partly closed. Wonder if I can find it?"
He entered the ruins, and ran up the staircase. A roseate twilight suffused the western sky. Led by the persistent sound, he came to the unroofed room facing the west. The moaning proceeded from some spot above his head. He tried to clamber up the mass of broken masonry that littered the floor, but found that he could not gain the level of the roof except by climbing the jagged brickwork of the broken wall, a feat too perilous in the half light.
"That's the worst of being fat," he said to himself. "I believe Armstrong could do it."
Leaving the room presently, he went idly, without definite motive, into the second room, facing east and overlooking the river and his uncle's grounds. In this direction dusk was already deepening into night; the nearer trees were still distinguishable, but beyond the river all individual objects were blurred by the darkness.
He sat on the paneless window-sill, listening to the strange sound from above, looking out towards the Red House, wondering whereabouts in the wide world his uncle was travelling. All at once, far away, almost on a level with his eyes, he thought he saw a faint red glow. It disappeared in a moment--so quickly that it seemed an illusion. But there it was again, indubitably some small luminous body. "Some one with a lamp in one of the top rooms of the Red House," he thought. Again it disappeared, only to show again after an interval--a third time--a fourth.