Giving her cousin an energetic good-night hug, she closed her eyes and was soon fast asleep.

Marian did not fall asleep at once. Her mind was working over the mystery of the purple flame. What was it? What had caused it? Who were the persons back there in the old dredge, and why had they come there? Such were some of the problems that crowded her mind.

The old dredge had been there for years. It was but one of the many monuments to men's folly in their greedy search for gold. These monuments-dredges, derricks, sluice-boxes, crushers, smelters, and who knows what others-lined the beaches and rivers about Nome. The bed of the Sinrock River was known to run fairly rich in gold. Someone had imagined that he might become rich by dredging the mud at the bottom of the river and washing it for gold. The scheme had failed. Doubtless the owner of the dredge had gone into bankruptcy. At any rate, here was the old dredge with its long beams and gaping iron bucket still dangling in air, rotting to decay. And here within this tomblike wreck had appeared the purple flame.

It had not been like anything Marian had seen before. "Almost like lightning," she mused, sleepily.

Being a healthy girl with a clean mind, she did not long puzzle her brain about the uncanny mystery of the weird light, but busied her mind with more practical problems. If these makers of the purple flame were to remain long at the dredge, how were they to live? Too often in the past, the answer to such a question had been, "By secretly preying upon the nearest herd."

The Sinrock herd had been moved some distance away. Marian's own herd was now the nearest one to the old dredge. "And when we move into winter quarters it will be five miles nearer. Oh, well!" she sighed, "there's no use borrowing trouble. It's probably some miners going up the river to do a.s.sessment work."

"But then," her busy mind questioned, "what about the purple flame? Why have they already stayed there three weeks? Why-"

At this juncture she fell asleep, to awake when the first streaks of dawn were casting fingers of light across the snowy tundra.

She crept softly from her sleeping bag, jumped into her clothes, and was in the act of lighting the fire when a faint sound of heavy breathing caused her to turn her head. To her surprise she saw Patsy, clothed only in those garments that had served as her sleeping gown, doing a strange, whirling, bare-footed fling of calisthenics, with the sleeping bag as her mat.

"You appear to have quite recovered," Marian laughed.

"Just seeing if I was all here," Patsy laughed in turn, as she dropped down upon the bag and began drawing on her stockings.

"Whew!" she puffed. "That's invigorating; good as a cold plunge in the sea. What do we have for breakfast?"

"Sour-dough flapjacks and maple syrup."

"Um-um! Make me ten," exclaimed Patsy, redoubling her efforts to get herself dressed.

That night Marian made a discovery that set her nerves a-tremble to the very roots of her hair and, in spite of the Arctic chill, brought beads of perspiration out on the tip of her nose.

As on the previous night, they had camped out upon the open tundra. This night, however, they had found a sheltered spot beside a clump of willows that lined a stream. The stream ran between low, rolling hills. Over those hills they had been pa.s.sing when darkness fell. Now, as Marian crept into the sleeping bag, she saw the nearer hills rising like cathedral domes above her. She heard the ceaseless rustle of willow leaves that, caught by an early frost, still clung to their branches.

This rustle, together with the faint breeze that fanned her cheeks, had all but lulled her to sleep. Suddenly she sat upright.

"It couldn't be!" she exclaimed. Then, a moment later, she added:

"But, yes-there it is again. Who would believe it? Lightning in the Arctic, and on such a night as this. Twenty below zero and clear as a bell! Not a cloud in sight."

Rubbing her brow to clear her mind from the cobweb of dreams that had been forming there, she stared again at the crest of the hill.

Then, swiftly, silently, that she might not waken her cousin, she crept from the sleeping bag. Donning her fur parka and drawing on knickers and deerskin boots, she hurried away from camp and up the hill, thinking as she did so:

"That's not lightning. I don't know what it is, but in the name of all that's good, I'm going to come nearer solving that mystery than ever I did before."

Half way up the hill she found a snow blown gully, and up this she crept, half hidden by the shadows. Nearing the crest, a half mile from her camp, she dropped on hands and knees and crawled forward a hundred yards. Then, like some hunter who has stolen upon his game, she propped herself on her elbows and stared straight ahead.

In spite of her expectations, she gasped at what she saw. A purple flame, now six inches in length, now a foot, now two feet, darted out of s.p.a.ce, then receded, then flared up again. Three feet above the surface of the snow, it appeared to hang in midair like some ghost fire.

Marian's heart beat wildly. Her nerves tingled, her knees trembled, and open-mouthed, without the power to move, she stared at this strange apparition.

This spell lasted for a moment. Then, with a half audible exclamation of disgust, she dropped limply to the snow.

"Inside a tent," she said. "Tent was so like the snow and the sky that I couldn't see it at first."

As her eyes became accustomed to this version of her discovery she was able to make out the outlines of the tent and even to recognize a dog sleeping beside it.

Suddenly the shadow of a person began dancing on the wall of the tent. So rapid were the flashes of the purple flame, so flickering and distorted was this image, that it seemed more the shadow of a ghost than of a human being. A second shadow joined the first. The two of them appeared to do some wild dance. Then, of a sudden, all was dark. The purple flame had vanished.

A moment later a yellow light flared up. Then a steady light gleamed.

"Lighted a candle," was Marian's comment. "It's on this side of them, for now they cast no shadows. Are they all men? Or, are there some women? How many are there? Two, or more than two? They are following us. I'd swear to that. I wonder why?"

Again she thought of the stories she had heard of ne'er-do-wells who dogged the tracks of reindeer herds like camp followers, and lived upon the deer that had strayed too far from the main herd.

"Perhaps," Marian mused, "they have heard that father's herd is to be run this winter by two inexperienced girls. Perhaps they think we will be easy. Perhaps-" she set her lips tight, "perhaps we will, and perhaps not. We shall see."

Then she went stealing back to her camp and crept shivering into the sleeping bag.

She slept very little that night. The camp of the mysterious strangers was too close; the perplexing problems that lay before her too serious to permit of that. She was glad enough when she caught the first faint flush of dawn in the east and knew that a new day was dawning.

"This day," she told herself, "we make our own camp. There is comfort in that. Let the future take care of itself."

She cast one glance toward the hill, but seeing no movement there, she began to search the ground for dry moss for kindling a fire.

Soon she had a little yellow flame glowing in her Yukon stove. The feeble flame soon grew to a bright red, and in a little while the coffee pot was singing its song of merry defiance to the Arctic chill.

CHAPTER III MARIAN FACES A PROBLEM

Marian buried her hand in the thick warm coat of the spotted reindeer that stood by her side and, shading her eyes, gazed away at the distant hills. A brown spot had appeared at the crest of the third hill to her right.

"There's another and another," she said. "Reindeer or caribou? I wonder.

If it's caribou, perhaps Terogloona can get one of them with his rifle.

It would help out our food supply. But if it's reindeer-" her brow wrinkled at the thought, "reindeer might mean trouble."

At that instant something happened that brought her hand to her side.

Quickly unstrapping her field gla.s.ses, she put them to her eyes.

A fourth object had appeared on the crest. Even with the naked eye one might tell that this one was not like the other three. He was lighter in color and lacked the lace-like suggestion against the sky which meant broad spreading antlers.

"Reindeer!" she groaned. "All of them reindeer, and the last one's a sled deer. His antlers have been cut off so he'll travel better. And that means-"

She pursed her lips in deep thought as the furrows in her brow deepened.

"Oh, well!" she exclaimed at last. "Perhaps it doesn't mean anything after all. Perhaps they're just a bunch of strays. Who knows? But a sled reindeer?" she argued with herself. "They don't often stray away."

For a moment she stood staring at the distant hillcrest. Then, seizing her drive line, she spoke to her deer. As he bounded away she leaped nimbly upon the sled and went skimming along after him.