ILTERING thinly down through the roof of snow and clean blue ice, the sharp winter sunshine made almost a summer's glow upon the brown bottom of the pond. Beneath the ice the water was almost as warm now as in summer, the pond being fed by springs from so deep a source that their temperature hardly varied with the seasons. Here and there a bit of water-weed stood up from the bottom, green as in June. But in the upper world, meanwhile, the wind that drove over the ice and snow was so intensely cold that the hardy northern trees snapped under it, and few of the hardy northern creatures of the wilderness, though fierce with hunger, had the fortitude to face it. They crouched shivering in their lairs, under fallen trunks or in the heart of dense fir thickets, and waited anxiously for the rigour of cold and the savagery of wind to abate. Only down in the pond, in the generous spaces of amber water beneath the ice-roof, life went on busily and securely. The wind might rage unbridled, the cold might lay its hand of death heavily on forest and hill; but the beavers in their unseen retreat knew nothing of it. All it could do was to add an inch or two of thickness to the icy shelter above them, making their peaceful security more secure.

The pond was a large one, several acres in extent, with a depth of fully five feet in the deeper central portions, which were spacious enough to give the beavers room for play and exercise. Around the shallow edges the ice, which was fully fifteen inches thick beneath its blanket of snow, lay solid on the bottom.

The beavers of this pond occupied a lodge on the edge of the deep water, not far above the dam. This lodge was a broad-based, low-domed house of mud, turf, and sticks cunningly interwoven, and rising about four feet above the surface of the ice-roof. The dome, though covered deep with snow, was conspicuous to every prowler of the woods, who would come at times to sniff greedily at the warm smell of beaver steaming up from the minute air-vents in the apex. But however greedy, however ravenous, the prowling vagrants might be, the little dome-builders and dam-builders within neither knew nor cared about their greed. The dome was fully two feet thick, built solidly, and frozen almost to the hardness of granite. There were no claws among all the ravening forest kindred strong enough to tear their way through such defences. In the heart of the lodge, in a dry grass-lined chamber just above high-water level, the beavers dwelt warm and safe.

But it was not from the scourge of the northern cold alone, and the ferocity of their enemies, that the beavers were protected by their ice-roof and their frozen dome. The winter's famine, too, they had well guarded themselves against. Before the coming of the frost, they had gnawed down great quantities of birch, poplar, and willow, cut them into convenient, manageable lengths, and dragged them to a spot a little above the centre of the dam, where the water was deepest. Here the store of logs, poles, and brush made a tangled mass from the bottom up to the ice. When it was feeding-time in the hidden chamber of the lodge, a beaver would swim to the brush pile, pull out a suitable stick, and drag it into the chamber. Here the family would feast at their ease, in the dry, pungent gloom, eating the bark and the delicate outer layer of young wood. When the stick was stripped clean, another beaver would drag it out and tow it down to the dam, there to await its final use as material for repairs. Every member of the colony was blest with a good appetite, and there was nearly always at least one beaver to be seen swimming through the amber gloom, either with a green stick from the brush pile, or a white stripped one to deposit on the base of the dam.

For these most diligent of all the four-foot kindreds this was holiday time. Under the ice-roof they had no dam-building, no tree-cutting, no house-repairing. There was nothing to do but eat, sleep, and play. There was not much variety to their play, to be sure; but the monotony of it did not trouble them. Sometimes two would indulge in a sort of mad game of tag, swimming at marvellous speed close beneath the ice, their powerful hind legs propelling them, their tiny little fore paws held up demurely under their chins, and their broad, flat, hairless tails stretched straight out behind to act as rudders. As they swam this way and that, they loosed a trail of silvery bubbles behind them, from the air carried under their close fur. At last one of the players, unable to hold his breath any longer, would whisk sharply into the mouth of the black tunnel leading into the lodge, scurry up into the chamber, and lie there panting, to be joined a moment later by his equally breathless pursuer. One by one the other members of the colony would dip in, till the low chamber was full of furry, snuggling warmth and well-fed content. Little cared the beavers whether it was night or day in the wide, frozen, perilous world above the ice-roof, whether the sun shone from the bitter blue, or the wolf-haunted moonlight lay upon the snow, or the madness of the blizzard made the woods cower before its fury.

As long as the cold endured and the snow lay deep upon the wilderness, the beavers lived their happy, uneventful life beneath the ice-roof. But in this particular winter the untempered cold of December and January, which slew many of the wood folk and drove the others wild with hunger, broke suddenly in an unprecedented thaw. Not the oldest bear of the Bald Mountain caves could remember any such thaw. First there were days on days, and nights on nights, of bland, melting rain, softer than April's. The snow vanished swiftly from the laden branches of fir and spruce and hemlock, and the silent woods stood up black and terrible against the weeping sky. On the ground and on the ice of pond and stream the snow shrank, settled, and assumed a grayish complexion. Water, presently, gathered in great spreading, leaden-coloured pools on the ice; and on the naked knolls the bare moss and petty shrubs began to emerge. Every narrow watercourse soon carried two streams,—the temperate, fettered, summer-mindful stream below the ice, and the swollen, turbulent flood above. Then the rain stopped. The sun came out warm and urgent as in latter May. And snow and ice together dwindled under the unnatural caress.

The beavers, in their safe seclusion, had knowledge in two ways of this strange visitation upon the world. Not all the soft flood of the melting snow ran over the surface of their ice, but a portion got beneath it, by way of the upper brooks. This extra flow disturbed both the colour and the temperature of the clear amber water of the pond. It lifted heavily against the ice, pressed up the tunnels to the very edge of the dry chamber of the lodge, and thrust ponderously at the outlets of the dam. Understanding the peril, the wise little dam-builders sallied forth in a flurry, and with skilful tooth and claw lost no time in enlarging the outlets. They were much too intelligent to let the flood escape by a single outlet, lest the concentrated flow should become too heavy for them to control it. They knew the spirit of that ancient maxim of tyrants, "divide et impera." By dividing the overflow into many feeble streams they knew how to rule it. This done, they rested in no great anxiety, expecting the thaw to end with a stringent frost.

Then, however, came the second, and more significant, manifestation of peril. The snow on the ice-roof had vanished; and looking up through the ice they saw the flood eddying riotously over the naked expanse. It was a portent which the wiser elders understood. The whole colony fell to work strengthening the dam where the weight of the current bore down upon it, and increasing the outlet along the farther edges.

A thaw so persistent, however, and at the same time so violent, overpassed their cunning calculations. One night, when all had done their best and, weary, but reassured, had withdrawn into the warm chamber of the lodge, something happened that they had never looked for. In their snug retreat they were falling to sleep, the rush of the overflow and the high clamour of the side vents coming dimly to their ears, when suddenly they were startled by the water being forced up over the dry floor of the chamber. The pressure of water beneath the ice had suddenly increased. They were more than startled. They were badly frightened. If the water should rise much higher they would be drowned helplessly, for the ice lay close all over the pond. The younger ones scurried this way and that with plaintive squeaks, and several dashed forth into the pond in a panic, forgetting that there was no escape in that direction. A moment later a low crashing penetrated to the dark chamber; and the invading water retreated down the tunnel. The ice-roof, worn thin, honey-combed, and upheaved by the pressure from below, had gone to pieces.

It was the older and wiser beavers who had remained in the chamber, terrified, but not panic-stricken. When the water retreated to its normal level,—about two inches below the chamber floor,—they were satisfied. Then, however, a louder and heavier note in the rush of the overflow came to their ears, and their anxiety returned with fresh force. Thrusting their whiskered noses inquiringly down the tunnel, they observed that the water was sinking far below its proper level. Well they knew what that meant. The dam was broken. The water, which was their one protection from the terrors of the forest, was escaping.

This was the kind of an emergency which a beaver will always rise to. Shy as they are, under ordinary circumstances, when the dam is attacked their courage is unfailing. In a moment every beaver in the colony was out among the swirling ice, under the broad, white moonlight which they had not seen for so long.

It was at its very centre, where the channel was deepest and the thrust of the water most violent, that the dam had given way. The break was about ten feet wide, and not, as yet, of any great depth. It was the comparatively narrow and unsubstantial crust of the embankment which had yielded, disintegrated by the thaw and ripped by the broken edges of the ice.

The vehemence of the torrent was rapidly cutting down into the firmer body of the dam, when the beavers flung themselves valiantly into the breach. In the face of the common danger they forgot all caution, and gave no heed to any hungry eyes that might be glaring at them from the woods on either shore. Without any apparent leadership in the work, they all seemed to help each other in whatever way would be most effective. Some dragged up the longest and heaviest poles from the pile of stripped stuff, floated them carefully into the break, butt end up-stream and parallel with the flow, and held them there doggedly with their teeth and fore paws till others could come with more timbers to hold the first lot down. Meanwhile, from the soft bottom along the base of the dam, big lumps of mingled clay and grass-roots, together with small stones to add weight, were grabbed up and heaped solidly upon the layers of sticks for anchorage. This loose stuff, though deposited along the upper ends of the sticks where the flow was least violent, and swiftly packed down into the interstices, was mostly washed away in the process. It was seemingly an even struggle, for a time, and the beavers could do no more than hold the breach from deepening and widening. But they were quite undaunted; and they seemed to know no such thing as fatigue. Little by little they gained upon the torrent, making good the hold of a mass of turf here, a few stones there, and everywhere the long straight sticks upon which the water could get but slight grip. The flood grew shallower and less destructive. More sticks were brought, more stones, and clay, and grass-roots; and then a layer of heavy, clean poles, over which the water slid thinly and smoothly without danger to the structure beneath.

The dam was now strongest at this point, its crest being broader and formed of heavier timbers than elsewhere. But no sooner had the hard-won victory been secured, and the plucky little architects paused for breath, than there came an ominous crackling from far over to the extreme left of the dam, where a subsidiary channel had offered a new vantage to the baffled torrent. The crackling was mingled with a loud rushing noise. Another section of the crest of the dam had been swept away. A white curtain of foam sprang into the moonlight, against the darkness of the trees.

II

While the brave little dam-builders had been battling with the flood, out there in the wide-washing moonlight, hungry eyes had been watching them from the heart of a dense spruce thicket, a little below the left end of the dam. The watching had been hopeless enough, as the owner of those fierce, narrow eyes knew it was no use trying to surprise a beaver in the open, when the whole pond was right there for him to dive into. But now when the new break brought the whole colony swimming madly to the left-hand shore, and close to the darkness of the woods, those watching eyes glowed with a savage expectancy, and began slowly, noiselessly, steadily, floating nearer through the undisturbed underbrush.

The tremendous thaw, loosing the springs and streams on the high flanks of Bald Mountain, had washed out the snow from the mouth of a shallow cave and rudely aroused a young bear from his winter sleep. As soon as he had shaken off his heaviness the bear found himself hungry. But his hunting thus far had not been successful. His training had not been in the winter woods. He hardly knew what to look for, and the soft slumping snow hampered him. One panic-stricken white rabbit, and a few ants from a rotten stump, were all that he had found to eat in three days. His white fangs in his red jaws had slavered with craving as he watched the plump beavers at their work, far out on the brightly moonlit dam. When, at last, they came hurrying toward him, and fell to work on the new break within thirty or forty yards of his hiding-place, he could hardly contain himself. He did contain himself, however; for he had hunted beaver before, and not with a success to make him overconfident. Right by the termination of the dam, where the beavers were working, the woods came down thick and dark to within eight or ten feet of the water. Toward this point he made his way patiently, and with such control of every muscle that, for all his apparent clumsiness, not a twig snapped, not a branch rustled, any more than if a shadow were gliding through them. He saw one old beaver sitting stiffly erect on the crest of the dam, a wary sentinel, sniffing the still air and scanning the perilous woods; but he planned to make his final rush so swift that the sentinel would have no time to give warning.

But the fierce little eyes of the bear, dark and glinting red, were not the only ones that watched the beavers at their valorous toil. In the juniper scrub, a short distance up the bank of the pond, crouched two big gray lynxes, glaring down upon the scene with wide, round, pale greenish eyes, unspeakably sinister. The lynxes were gaunt with famine. Fired with the savage hope that some chance might bring a beaver within reach of their mighty spring, they had crept down, on their great, furred, stealthy pads, to the patch of juniper scrub. Here they had halted, biding their time with that long, painful patience which is the price of feeding—the price of life—among the winter-scourged kindreds. Now, when the beavers had so considerately come over to the edge of the woods, and appeared to be engrossed in some incomprehensible pulling and splashing and mud-piling, the two lynxes felt that their opportunity had arrived. Their bellies close to the snow, their broad, soft-padded feet stepping lightly as the fall of feathers, their light gray fur all but invisible among the confused moon-shadows, their round, bright eyes unwinking, they seemed almost to drift down through the thickets toward their expected prey.

Neither the bear creeping up from below the dam, nor the two lynxes stealing down from above it, had eyes or thought for anything in the world but the desperately toiling beavers. Their hunger was gnawing at their lean stomachs, the fever of the hunt was in their veins, and the kill was all but within reach. A few moments more, and the rush would come, up from the fir thickets—the long, terrible spring and pounce, down from the juniper scrub.

The work of repairing the breach was making good progress. Already the roaring overflow was coming into subjection, its loud voice dwindling to a shallow clamour. Then, something happened. Perhaps the wary sentinel on the crest of the dam detected a darker shade stirring among the firs, or a lighter grayness moving inexplicably between the bushes up the bank. Perhaps his quick nostrils caught a scent that meant danger. Perhaps the warning came to him mysteriously, flashed upon that inner sense, sometimes alert and sometimes densely slumbering, which the forest furtiveness seems to develop in its creatures. However, it came, it came. Dropping forward as if shot, the sentinel beaver brought his flat tail down upon the surface of the water with a smack that rang all up and around the borders of the pond, startling the quiet of the night. In a fraction of a second every beaver had vanished beneath the shining surface.

At the same moment, or an eye-wink later, a strange thing happened—one of those violent surprises with which the vast repression of the forest sometimes betrays itself. Maddened to see his prey escaping, the bear made his rush, launching himself, a black and uncouth mass, right down to the water's edge. Simultaneously the two lynxes shot into the air from higher up the bank, frantic with disappointed hunger. With a screech of fury, and a harsh spitting and snarling, they landed a few feet distant from the bear, and crouched flat, their stub tails twitching, their eyes staring, their tufted ears laid back upon their skulls.

Like a flash the bear wheeled, confronting the two great cats with uplifted paw and mouth wide open. Half-sitting back upon his haunches, he was ready for attack or defence. His little eyes glowed red with rage. To him it was clearly the lynxes who had frightened off the beavers and spoiled his hunting; and interference of this kind is what the wild kindreds will not tolerate. To the lynxes, on the other hand, it was obvious that the bear had caused the whole trouble. He was the clumsy interloper who had come between them and their quarry. They were on the verge of that blindness of fury which might hurl them, at any instant, tooth and claw, upon their formidable foe. For the moment, however, they had not quite lost sight of prudence. The bear was master of the forest, and they knew that even together they two were hardly a match for him.

The bear, on the other hand, was not quite sure that he was willing to pay the price of vengeance. His blood surging in the swollen veins, he growled with heavy menace, and rocking forward upon his haunches he seemed on the point of rushing in. But he knew how those powerful knife-edged claws of the lynxes could rend. He knew that their light bodies were strong and swift and elusive, their teeth almost as punishing as his own. He felt himself the master; nevertheless he realized that it would cost dear to enforce that mastery. He hesitated. Had he made the slightest forward move, the lynxes would have thrown caution to the winds, and sprung upon him. On the other hand, had the lynxes even tightened up their sinews to spring, he would have hurled himself with a roar into the battle. But as it was, both sides held themselves in leash, tense, ready, terrible in restraint. And as the moments dragged by, out on the bright surface of the pond small heads appeared, with little bright eyes watching curiously.

For perhaps three or four long, intense minutes there was not a move made. Then the round eyes of the lynxes shifted ever so little, while the bear's eyes never faltered. The bear's was the steadier purpose, the more tenacious and resolute temper. Almost imperceptibly the lynxes shrank backward, gliding inch by inch. A swift side-glance showed them that the way of retreat was open. Then, as if both were propelled by the one vehement impulse, they bounded into the air, one whirling aside and the other almost doubling back upon his own trail. Quicker than it takes to tell it, they were fleeing like gray shadows, one over the bank and through the juniper bushes, the other up along the snowy shore of the pond, their discomfiture apparently driving them to part company. The bear, as if surprised, sat up on his haunches to stare after them. Then, with a hungry look at the beavers, now swimming openly far out in the moonlight, he turned and shambled off to find some more profitable hunting.

For a few minutes all was stillness, save for the rushing of the water over the dam. The solitude of the night had resumed its white and tranquil dominion as if nothing had ever occurred to jar its peace. Then once more the watchful sentinel appeared, sitting erect on the dam, and the diligent builders busied themselves to complete the mending of the breach.