"If only we can make that channel," she panted. "If the water's deep enough all the way to it, we can. Or if the floe doesn't come too fast."

Florence, who thought she had expended every ounce of energy in her body, took three long breaths, then, having hooked her pole to the prow of the O Moo, began to pull. Soon Marian joined her on the pole and together the girls struggled.

By uniting their energies they were able to drag the reluctant O Moo length by length toward the goal.

Once Florence, having entrusted her weight to a rotten bit of ice, plunged into the chilling waters. But by Marian's aid she climbed upon a safer cake and, shaking the water from her, resumed her t.i.tanic labors.

Twice the hull of the O Moo touched bottom. Each time they were able to drag her free.

At last with a long-drawn sigh they threw their united strength into a shove which sent her, prow first, up the still waters at the mouth of the stream.

There remained for them but one means of reaching sh.o.r.e--to swim.

With a little "Oo-oo!" Marian plunged in. She was followed closely by Florence.

Twenty minutes later they were in the cabin of the O Moo and rough linen towels were bringing the warm, ruddy glow of life back to their half-frozen limbs. The O Moo was lying close to the bank where an overhanging tree gave them a safe mooring.

As Florence at last, after having drawn on a garment of soft clingy material and having thrown a warm dressing gown over this, sank into a chair, she murmured:

"Thanks be! We are here. But, after all, where is 'here'?"

CHAPTER XIV "A PHANTOM WIRELESS"

It was night, dark, cloudy, moonless night. Florence could scarcely see enough of the sandy beach to tell where she was going. She had, however, been over that same ground in the daytime, so she knew it pretty well.

Besides, she wasn't going any place; just walking back and forth, up and down a long, narrow stretch of hard-packed and frozen sand.

She was thinking. Walking in the darkness helped her to think. When there is nothing to hear, nothing to see and nothing to feel, and when the movement of one's feet keeps the blood moving, then one can do the best thinking. Anyway that was the way this big, healthy, hopeful college girl thought about it. So she had wrapped herself in a heavy cape and had come out to think.

They had been ice-locked on the island for thirty-six hours. The ice had crowded on sh.o.r.e for a time. It had piled high in places. Now the wind had gone down and it was growing colder. It seemed probable that the ice would freeze into one solid ma.s.s, in which case they would be locked in for who knows how long.

The water in their little natural harbor had taken on something of a crust. It was possible that the boat would be frozen into the stream.

"Not that it matters," she told herself rather gloomily. "We can't start the engine and as long as we can't it is impossible for us to leave the island; only thing we can do is wait until someone discovers our plight or we are able to hail a boat."

They were on an island; they had made sure of that first thing. She and Marian had gone completely around it. It wasn't much of an island either.

Just a wreath of sand thrown up from the bottom of the lake, it could scarcely be more than three miles long by a half mile wide. The stream they had entered, running almost from end to end of it, drained the whole of it. The highest point was at the north. This point was a sand dune some forty feet high. Their boat was moored at the south end. The entire island, except along the beach, was covered with a scrub growth of pine and fir trees. As far as they could tell, not a single person had ever lived on the island.

"It's very strange," Marian had said when they had made the rounds of it.

"It doesn't seem possible that there could be such an island on the lake without summer cottages on it."

"No, it doesn't," Florence had answered. "What an ideal spot! Wonderful beaches on every side. Fishing too, I guess. And far enough from land to enjoy a cool breeze on the hottest day of summer."

Though they had constantly strained their eyes in an endeavor to discover other land in the distance, they had not succeeded.

"Probably belongs to someone who will not lease it," said Florence at last.

So here she was trying to think things through. There was danger of a real catastrophe. The food in their pantry could not possibly last over ten days. Then what? As far as she knew, there was not a thing to be eaten on the island. It was possible that fish could be caught beneath the lake ice or in their stream. She meant to try that in the morning.

"What a plight to put one in!" she exclaimed. "Who could have done it and why did they do it?"

This question set her mind running over the mysterious incidents which, she could not but believe, had led up to this present moment.

There had been Lucile's seeing of the blue face in the old Mission, her own affair with the stranger in the museum; the blue candlestick; the visit to Mr. Cole in the new museum; Lucile's frightful adventure on the lake ice; the incident of the two men with the sled on the ice of the lagoon and the single man sitting on the ice; then the spot of blue ice discovered next day.

"Blue ice!" she exclaimed suddenly, stopping still in her tracks. "Blue!

Blue ice!"

Florence frowned, as she considered it.

A new theory had come to her regarding that spot of blue ice on the lagoon, a theory which made her wish more than ever to get away from this island.

"Ho, well," she whispered at last, "there'll probably be a thaw before we get back or those men will come back and tear it up. But if there isn't, if they don't then--well, we'll see what we'll see."

She was still puzzling over these problems when a strange noise, leaping seemingly out of nowhere, smote her ear.

It was such a rumble and roar as she had heard but once before in all her life. That sound had come to her over a telephone wire as she pressed her ear to the receiver during a thunderstorm. But here there was neither wire nor receiver and the very thought of a thunderstorm on such a night was ridiculous.

At first she was inclined to believe it to be the sound of some disturbance on the lake, a sudden rush of wind or a tidal wave.

"But there is little wind and the sea is calm," she told herself.

She was in the midst of these perplexities when the sound broke into a series of sput-sput-sputs. Her heart stood still for a second, then raced on as her lips framed the word:

"Wireless."

So ridiculous was the thought that the word died on her lips. There was no wireless outfit on the yacht; could be none on the island, for had they not made the entire round? Had they not found it entirely uninhabited? Whence, then, came this strange clash of man-made lightning?

The girl could find no answer to her own unspoken questions.

After a moment's thought she was inclined to believe that she was hearing the sounds created by some unknown electrical phenomena. Men were constantly discovering new things about electricity. Perhaps, all unknown to them, such isolated points as this automatically served as relay stations to pa.s.s along wireless messages.

Not entirely satisfied with this theory, she left the beach and, feeling her way carefully among the small evergreens, came at last to the base of a fir tree which capped the ridge. This tree, apparently of an earlier growth, towered half its height above its fellows.

Reaching up to the first branch she began to ascend. She climbed two-thirds of the way to the top with great ease. There she paused.

The sound had ceased. Only the faint wash-wash of wavelets on ice and sh.o.r.e, mingled with the mournful sighing of the pines, disturbed the silence of the night.

For some time she stood there clinging to the branches. Here she caught the full sweep of the lake breeze. She grew cold; began to shiver; called herself a fool; decided to climb down again, and was preparing to do so, when there came again that rumbling roar, followed as before by the clack-clack-clack, sput-sput.

"That's queer," she murmured as she braced herself once more and attempted to pierce the darkness.

Then, abruptly, the sound ceased. Strain her ears as she might she caught no further sound. She peered into the gloom, trying to descry the wires of an aerial against the sky-line, but her search was vain.

"It's fairly spooky!" she told herself. "A phantom wireless station on a deserted island!"

Ten minutes longer she clung there motionless. Then, feeling that she must turn into a lump of ice if she lingered longer, she began to climb down.