Will returned to the Mill House that night rather later than he should have been, after a long chat with the artist, and the first thing he learned was that his father had gone to bed with a bad headache.

It was his own time, too, and he hurried up to his bedroom, when, like a flash, came the recollection of the strange sounds he had heard.  It was too late to go out again, so he opened the window and leaned there, listening; but from that position he could hear the roar of many waters ­nothing more.

As a rule, Will’s habit was to bang his head down on the pillow and draw one very deep, long, restful breath, as he stretched himself at full length, and the next moment he was asleep.

Somehow, on this particular night, when he went through his customary movements, the result was that he was more wide-awake than ever.  Then for quite two hours he twisted, turned, stretched himself, yawned, got out of bed and drank cold water, bathed his face, walked up and down, tried to count a hundred forwards, then backwards, counting sheep going through a gap, did everything he could think of, and even thought of standing upon his head to see if that would do any good; but sleep would not come.

“Am I going to be ill?” he asked himself, and while he was waiting for the answer he dropped off soundly.

But for no pleasant rest, for it was into nightmare-like dreams of some great trouble.  While he was trying to sleep, all recollection of the mysterious sounds was in abeyance; but they attacked him again in his dreams, with this peculiarity, that he seemed to know now exactly where they were.  He was able to locate them precisely.  There they were ­ hammer, hammer, hammer, throb, throb, throb, till it was almost maddening.

He tried to escape from them; he longed to get away; but there they were in the deep darkness, hemmed in by the deep booming chorus of the falling waters ­the only part of his dreams that was real.

For during the whole night, through the sluices, along the chute, and over the wheel, the waters continued their course, keeping down the overburdened pool to the same level, for once more heavy rains in the hills rushed along the stream to augment the supply.

It was with a feeling of intense relief that the boy woke at last in the faint dawn of morning, sprang from the bed, and rushed to the open window again, to thrust his burning brow out into the cool, fresh air.  The beating in his brain was gone, his mind was clear, and he strained out to try whether he could hear through the roar of falling waters the hammering that had tormented him all through the night.

“No,” he said, “it’s impossible to hear it from this window;” and he hurriedly dressed, to make his way out and up to the spot where he had stood with his friends.

“Nothing now,” he said.  “Could it have been fancy?”

He listened for a few minutes longer, and then mounted the rough steps, to stand on the top of the great stone wall to listen from there once more, before gazing up the valley and noticing that there were two little clusters of wild-ducks busily feeding just at the mouth of the stream where it entered the pool.  There was a faint glow in the east, and flecks of gold high towards the zenith, promises of a glorious day, and he turned slowly, hesitating as to whether he should go back to bed.

“No!  Rubbish!” he said.  “I’ll go and rouse up old Josh.  Yes, and wake up Mr Manners, too.  He’d like to see this glorious sky ­ah! what’s that?”

That was something unusual which had just caught his eye, for as he spoke he turned to look right along the top of the dam, where he seemed to see a strange disturbance on the surface of the water just at the end where the wall joined the rugged cliff.

“It must be a great trout,” he said, “one that’s being beaten against the stones, and is half-dead.  No; I believe it’s an otter.”

He ran along the top of the wall and looked down in wonder, to see that a strange whirlpool seemed to have been formed, where twigs of dead wood, bits of grass, and autumn leaves were sailing round and round, before being sucked down a central hole.

“What does that mean?” he thought; but he acted as well as thought, going quite to the edge of the wall, and then descending the steep built-up slope of stones and cemented earth, to where at the base of the dam-wall he found himself face to face with a sight so suggestive of peril that he turned at once and ran for the mill.

For there below, gushing as it were from the bottom of the wall, was a little stream ­a little fount equalling in bulk the tube-like shape formed by the swirling water he had noticed far above.

The quantity was small, and quite a tiny stream ran down the valley, cutting itself a channelled course; but Will knew enough ­knew the power of water, and what such a tiny stream could do.  In short, in those brief moments he had grasped the fact that a dangerous flaw had been formed in the dam, which, if unchecked, might mean destruction to them all.

“Father!  Father!” cried Will, rushing into his father’s bedroom.

“I’m afraid it’s worse, my boy,” was the reply.  “I’ll lie still for a few hours and see if my headache passes off.”

“Father, wake up; you don’t understand ­the water’s breaking through the dam!”

There was a heavy bump on the floor, which made the wash-hand jug rattle in the basin, as Mr Willows sprang out of bed, with his headache quite cured by the nervous shock.

“Do you mean it?  Are you sure?”

“Yes, father, it’s twice as big now as it was when I saw it first.”

“Ah!” ejaculated Mr Willows, and he stood for a moment with brow knit and fists clenched, like a man gazing inwards.

“Run to the big bell, boy, and pull with all your might!”

“Yes, father.  Is it very dan ­”

“Run!  Act!” was the reply, and in a few seconds the great bell was sending its notes in what seemed to the boy a harsh jangle, such as he had never heard before.

Rung at such a time and in such a manner, it carried but one message to those who heard ­Danger! ­and in a very short time the work-people came hurrying from the cottages which formed a scattered village down the vale, to where their master was standing on a block of stone where he could be well seen, waiting to give his orders.

“You, Dacey,” he shouted to the first man, “take one of the horses ­ don’t stop to saddle ­and gallop right down the vale, giving the warning.  Stop nowhere ­shout as you go by each cottage, `The dam bursts!’”

The man was off, and, while Willows was giving fresh orders, the clatter of the horse’s hoofs was heard, and the man passed out of sight.  Meanwhile, from the directions Willows was giving, the alarm was spreading fast, men’s voices giving it everywhere.

There were a few women’s shrieks heard, children began to cry, and there was wild excitement about the Mill House.  Women’s voices, too, were heard remonstrating, and words were uttered about saving this or that; but Willows rushed up to the first group, and shouted ­

“Silence, there!  Save your lives!  Up the sides as fast as you can, and as high as you can climb.  At any moment the dam may be washed away like so much salt.  Think of nothing but your lives!”

A wild yearning cry full of despair arose at this, but the master’s words went home, and the next minute the hurried scrambling of feet was heard, as women, carrying their children, began to climb up the sides of the vale, dragged and pushed up by the menfolk, in whose faces were seen reflected the looks of their chief; but to a man they were grim and stern; and all the while, harsh, wild and strange, bringing down as it were a shower of echoes of its tones, the great bell rang on, swung to and fro, and over and over under the feverish impulse given by Will’s untiring arms.

So effective were the commands, so deeply imbedded in every breast was the knowledge of what might happen, that the time seemed short before Mr Willows could draw breath and feel satisfied that the weaker portion of the community were in safety.

“Now,” he cried, “you who are old, and all you boys, follow the women.  No words ­Go!  Now, my lads, you who are ready to work, let’s see what we can save.  But, mind, it must be one eye for what you are doing and one for yon tottering wall.”

“Why, master,” shouted the north-country man, “I don’t see nowt.  She’ll stand for long after we are passed away.  Aren’t this all a skear?”

“No!” cried Willows, fiercely.  “The strong dam is wounded, and the place is bleeding fast.  Here, Will,” he shouted, “leave that bell!”

“Oh, father,” cried the boy, as he ran up, “don’t send me away at a time like this.”

“I am not going to, my boy; I want you to be my strong right hand.  Now then, I shall not be with you, so watch for your safety and that of those who are with you.  Take four men, and save the books first, then the chest, and all you can that is easiest to move.  Scatter the things anywhere that they will lodge, as soon as they are higher than the dam.  Off with you!  Work for your lives!  One more word of warning!  When the wall goes, if go it does, it will be with one mighty rush, sweeping everything away.  Now, six men with me!”

All the rest rushed to him, and he told off the number he required.

“You others,” he cried, “you have heard what I’ve said.  Off with you, and try to save your most treasured possessions ­by your, I mean those of your neighbours and yourselves.  At a time like this all must be in common, as it shall be when, if, please God, we escape, I will try to make up to you for what you have lost.  Off!  Now, my lads, every man lift and bear as big a stone as you can.  Follow me!”

The next minute, headed by their chief, a line of men, like ants from a disturbed hill, were seen staggering beneath their burdens up the rugged steps to the top of the dam.

“Phew!  This here’s a heavy one!” panted the north-country man as they reached the top.  “Say, maister, it’ll be dangerous to be safe for us if the wall goes now.”

The words were uttered in such a cheery tone, that, in spite of their peril, a hearty laugh rose from the party, and, as Mr Willows paused for a moment to gaze downward and see how on both the steep sides of the valley his commands were being carried out, a grim smile for a moment relaxed his tightened lips.

“Now,” he cried, “do as I do,” as he bent himself to his task, and stepping to the end of the wall where the whirlpool seen first by Will had begun to look more worthy of its name ­for it was three times as swift and mighty as at its birth ­he leaned forward and softly dropped in the great stone he carried, and stood back to let the others follow suit.

“It seems a mere nothing,” he said, as the last stone was cast, “but it is all that we can do, and we must keep on.”

“Ahoy, there!” came from the opposite end just then.  “What’s the matter, Mr Willows?” and the burly figure of the artist came hurrying across the dam.  “Not safe?”

There was another hail, and the Vicar came hurrying down the path, preceded by his son.

“Why, Willows,” he cried, breathlessly, “surely the dam is not giving way?”

“Oh, father!” faltered Josh.  “It must be that ­that ­”

“What do you mean, boy?  Speak!”

“It is something to do with the noise we all heard last night.”

At that moment, with the rising sun shining full upon his fierce, contracted face and glistening bald head, Drinkwater stood leaning out from the farther bank, holding tightly with one hand to an overhanging birch, and if ever countenance wore a fiendish smile, it was his.