"The old chap kept a boat, evidently," said Pratt. "There ought to be a path from here to the house, but there's no sign of one. Let's strike inland, and see if we can trace it somewhere."

They pushed through the thicket, here as closely tangled as anywhere else, and emerging suddenly into the wilderness garden, in which perennial plants were stifling one another, they saw the ruined cottage before them.

"Jolly picturesque," said Pratt, halting. "I dare say distance lends enchantment to the view; no doubt it's a pretty dismal place inside; but the sunlight makes a gorgeous effect with those old walls. The creepers running over warm red bricks--it's a harmony of colour, old man. I'd like to make a sketch of it."

"Houses were built to be lived in," grunted Armstrong.

Pratt made no reply at once. For the moment the schoolboy was sunk in the artist. He let his eyes linger on the spectacle--the broken roof; the one gable that here survived; the creepers straggling round it and over the gla.s.sless window of the room beneath; the heap of shattered brick-work at the base, half-clothed with greenery and gay with flowers.

"Of course, it looked very different by moonlight," he said at last.

"You'd lose all the colour. Still----"

"I saw it from the other side," said Armstrong. "That won't please you so much--it's not so much ruined."

"Well, let's go and see."

He was leading through the riot of untended flowers, Armstrong close behind him, when he stopped suddenly, and in a tone of voice involuntarily subdued, asked--

"Did you see that?"

[Ill.u.s.tration: "'DID YOU SEE THAT?'"]

"What?" said Armstrong, starting in spite of himself.

"A figure--something--I don't know; at the back of the room."

The sunlight, slanting from the south-east, shone full upon the cottage, but left the back of one of the rooms on the ground floor shadowed by the screen of creepers falling over the gaping window.

"Well, suppose there was, why the mysterious whisper?" said Armstrong, his own doubts and remembered tremors disposing him to ridicule Pratt's excitement. "Why shouldn't there be some one there? _We_ are here--why not others?"

"Yes, but--well, I didn't expect it. Perhaps you did."

"It may have been only the shadow of the creeper on the wall."

"It may have been your grandmother! Let's get into the place and have a look round. The window's too high to climb; is the door open?"

"There's no door."

"So much the better. Come on."

They hastened to the front, and through the doorway into the hall. The house was silent as a tomb. On either side opened a doorless room.

They entered the one on the right--that in which Pratt had believed he saw a moving figure. It was pervaded by a subdued greenish sunlight, becoming misty by reason of the dust their footsteps had stirred up. It held neither person nor thing. They crossed to the opposite room, which, being out of the sunshine, was in deep gloom. This, too, was empty. Pa.s.sing the staircase they arrived at the back premises, a stone-flagged kitchen and scullery. Both were bare; even the grate had been removed.

"Now for upstairs," said Pratt. "They've made a clean sweep down here."

They mounted the staircase, at first treading carefully, then with confident steps as they found that the creaking stairs were sound.

There were four rooms on the upper storey, two of them exposed to the sky. Of these the floors were thick with blown leaves, twigs, birds'

feathers, fragments of tiles and bricks, broken rafters, and the debris of the ceiling. The other two, roofed and whole, were as bare as the rooms below. Through the empty cas.e.m.e.nt of one they caught sight of the tower in the grounds of Mr. Ambrose Pratt's house, and the upper windows and roof of the house itself. Pratt's appreciative eye was instantly seized by the prospect--the foreground of low thicket; the glistening stream; the n.o.ble trees beyond, springing out of a waving sea of sun-dappled bracken; the gentle slope on whose summit stood the buildings, and in the far background the rolling expanse of purple moorland. For the moment he forgot the shadowy figure he had seen, and lingered as if unwilling to miss one detail of the enchanting landscape.

"There's no one here," said Armstrong, matter-of-fact as ever.

"I dare say it was an illusion. Look how the sunlight catches the ripples, Jack. And did you see that kingfisher flash between the banks?"

"I'll go and have another look downstairs," Armstrong responded. "I'll give you a call if I find anything."

He felt, as he went down, that perhaps he would have done better to be candid with Pratt. Why make any bones about an incident capable, no doubt, of a simple explanation? The tramp, if tramp he was, had, of course, the objection of his kind to being found on enclosed premises, even though they were a ruin. Yet it was strange that he had left no tracks--had he not? Armstrong was suddenly aware of something that had hitherto escaped him. There was no dust, no litter on the stairs.

Singular phenomenon in a long-deserted house! And surely the floor of the room in which Pratt now stood, unlike the other floors, was clear.

It, and the staircase, must have been swept. Why? Not for tidiness--no tramp would bother about that. For what, then? Secrecy? Dusty floors would leave tell-tale marks--and with the thought Armstrong hurried down to the room in which the figure had been seen, and examined the floor.

Yes! besides the footprints of himself and Pratt between door and window, there were others along the wall at the back of the room. The fellow must have slipped out with the speed of a hare. Armstrong perceived at once the clumsiness of the attempt at secrecy, for the very fact that some of the floors were swept gave the game away. At the same time, he was puzzled to account for the man's motive. The island was deserted; it was no longer the scene of picnics; the villagers avoided it; why then should a casual visitor--for there was no evidence of continuous occupation--be at the pains even to try to cover up his movements? The strange oppression of the previous night returned upon Armstrong's mind, and he roamed about the lower floor in a mood of curious expectancy.

He came once more to the kitchen, and noticed that between it and the scullery was a closed door--the only door that remained in the house.

Instinctively bracing himself, he turned the handle; the door opened, disclosing a dark hole and a downward flight of stone steps. He went down into the darkness, at the foot of the steps struck a match, and found himself in a low, s.p.a.cious cellar, empty except for a strewing of coal dust. As the match flickered out he caught sight of something white in a corner. Striking another, he crossed the floor and picked up a jagged sc.r.a.p of paper, slightly brown along one edge. At the same moment he observed a little heap of paper ashes.

Throwing down the match he trod upon it, and turned, intending to examine the paper in the daylight above. Pratt's voice shouting, and a sound of some one leaping down the staircase to the hall, caused him to spring up the steps two at a time.

"What's up?" he shouted back, unable to distinguish Pratt's words.

He reached the hall just in time to see Pratt dash through the doorway and sprint at headlong pace towards the river. Stuffing the paper into his pocket, Armstrong doubled after him. Pratt was already plunging into the thicket, and, when Armstrong came within sight of the channel, the other had flung off his cap and blazer, and was diving into the stream.

[Ill.u.s.tration: "THE OTHER WAS DIVING INTO THE STREAM."]

"What mad trick----"

He cut short his exclamation, for his long strides had brought him to the pier, and he saw the cause of Pratt's desperate haste. The motor-boat, broadside to the stream, was drifting down the channel.

Already it was some thirty yards beyond the spot where Pratt had taken the water, and Pratt was swimming after it with the ease of a water-rat.

Feeling that there was no reason why himself should get soaked too, Armstrong forged his way through the vegetation at the brink of the channel, but made slow progress compared with the swimmer. Pratt was rapidly overhauling the boat. Watching him, instead of his own steps, Armstrong tripped over a creeper, and fell headlong. By the time he had picked himself up, Pratt had disappeared. Armstrong's momentary anxiety was banished by the sight of the boat moving slowly in towards the sh.o.r.e of the island.

"Good man," he shouted. "You headed it off splendidly."

Pushing and swimming, Pratt was evidently making strenuous efforts to drive the boat into the bank before the current swept it past the island. If he failed, Armstrong saw that he would have to change his tactics and run it ash.o.r.e on the left bank--his uncle's property. It would then be necessary for Armstrong to swim across, for Pratt had never taken the trouble to learn the working of the engine.

"Stick it, old man," he called.

In a few moments more Pratt contrived to edge the boat among the low branches of an overhanging tree. Its downward progress thus partly checked, he was able to exert more force in the sh.o.r.eward direction.

When Armstrong, after a rough scramble, arrived at the spot, he had just rammed the boat's nose securely into a tangled network of branches, and was clambering, a dripping, bedraggled object, up the bank.

A prolonged "Coo-ee!" sounded from far up the river.

"There's old Warrender, shrieking like a bereaved hen," said Pratt, shaking himself. "And it's all through his not tying the thing up properly! Armstrong, water is very wet."

"I say, did you ever know Warrender not tie it up properly?"

"How else would it break away?"

"You didn't see it break away?"

"No, you can't see our camping-place from the ruins. It was a good way down before I caught sight of it."