But just after sunset, when the glow had faded, and the first thin wave of lilac and amber came washing coolly over the wide landscape, and the blossoms gave out new scents at the touch of the dew, and the night-hawks twanged in the pale green upper heaven, then the Gray Visitor awoke to eager activity. He floated upward from out his covert like a ghost from a pool, circled over it twice, and flew off to those high and lonely treetops which he had marked in the earlier part of the day.

In the nearest tree, not far from the top, was what looked like an immense accumulation of dead sticks. To the Gray Visitor, coming from a region so far north that there were no tall treetops, this dark mass had no significance. In his world of the Arctic barrens nothing of the nature of a nest would ever be built in such an exposed position, where the first icy hurricane screaming down from the Pole would rip it to shreds. Therefore it never occurred to him that the clumsy platform of dead sticks was the nest of a pair of blue herons. In fact, he had no idea that any such creature as a blue heron existed. He flew noiselessly to the very top of the tree and perched there some ten or a dozen feet above the dusky platform of sticks.

All the wide, glimmering twilight world beneath him was very still and quiet. Nothing seemed astir but the two or three night-hawks swooping and twanging high up in the hollow heaven, and he had no thought of hunting any such elusive quarry as the night-hawks. With a view to startling some wary hiders into activity, he opened his beak and gave utterance to an unearthly screeching hoot. As he did so, there was a sharp movement on the platform of sticks, and a keen, defiant eye looked up at him. He discerned instantly that the platform of sticks was a nest, and that an immense bird, with an astonishingly long head and bill, was sitting upon it.

In his own desolate north the great gray owl knew that no creature on wings could rival him. He was the undisputed tyrant of the Polar air, even the dashing, white chocolate-mottled hawk-owl flying precipitately before him. It never occurred to him that this straight-billed nester could be in any way dangerous. He dropped down upon her quite casually, as upon a sure and easy victim.

But, before he was within striking distance, the narrow head of the heron was drawn far back between her shoulders, and the long straight javelin of her bill presented its point directly toward the attack.

The Gray Visitor noted what a weapon confronted him, and paused warily. In the next instant the snaky neck of the heron uncoiled itself and the javelin bill darted up at him like lightning. It was a false stroke on the heron's part, for her assailant was not quite within reach. But the Gray Visitor took note of the deadly possibilities of that darting bill, and promptly sailed a little further out of its range.

But he was only warned, not daunted. For several minutes he circled slowly just above the nest, now approaching, now retiring, while he pondered the unaccustomed problem. And all the time the heron, her head drawn back between her hunched shoulders, watched his flight unwinkingly, and kept her menacing point at guard. On the flexible coil of her neck her head pivoted perfectly, and from whichever quarter the enemy approached, there was that fiery yellow point always confronting him, waiting to dart upward and meet him full in the breast.

Suddenly he swooped again. Up came that darting stroke to meet him. But he did not meet it. Swerving craftily, he caught the stroke in his wing feathers and smothered it, buffeting it down. With a harsh quah-ah of despair, the heron strove to regain her position for another stroke. But already her adversary had his clutch upon her throat. A moment more and the long neck straightened out, and the narrow head hung limply over the edge of the nest. The eggs, crushed in the struggle, oozed slowly down through the loose foundations of the platform, and the great gray owl began to tear greedily at the most lavish banquet his hunting had ever won him.

But Nature is apt to deal remorselessly with the unprepared. And the Gray Visitor, not being at home with his surroundings, had neglected to prepare for the return of the dead mother's mate. Busy at his feasting, he failed to notice at first the flapping of heavy wings. When he did notice it he looked up sharply, his beak dripping, his round, pallid face dappled with blood. The tall cock-heron was just settling upon the edge of the platform. His head was drawn back between his shoulders, behind the long yellow lance of his bill, and his eyes, hard as jewels, met those of the murderer without any expression of rage or fear or hate. They were as unchanging as the gemmed eyes of an idol.