"Those questions," smiled Florence, "must be answered one at a time, but I have faith that they will both be answered and that we'll be back in the dear old city for Christmas."

"Christmas?"

"Two weeks off. Next week is final exams. We've just got to be back for them."

"In that case let's have a look at the engine."

A half hour later the two girls, dressed in greasy overalls, their hair done in knots over their heads, their hands black with oil, might have been seen engaged in the futile attempt to unravel the mysteries of the small gasoline engine, which, in other days, had been used to propel the O Moo when the wind failed to fill her sails.

"We might be able to sail her home," suggested Marian.

"Might," said Florence.

Risking a look out on deck, she opened a door. Her eyes swept the s.p.a.ce before her. Her lips uttered a low exclamation:

"Gone! Mast, canvas, everything. We can't sail home, that's settled."

Mark Pence, after his strange adventures at the old scow, was marched off to the police station, where he was allowed to doze beside the radiator until morning.

Soon after daybreak he was motioned to a desk, where a sergeant questioned him closely regarding his knowledge of the events of the night and of the Orientals who lived in the old scow.

He was able to tell little enough and to explain next to nothing. When he had told of the disappearance of the O Moo, of the grease on the tracks, of the sample he had saved and of the block of wood with the cross embossed upon it, the officer proposed that they should together make a trip to the beach and go over the grounds.

"But these friends of mine? These girls in the O Moo?" he protested.

"Oh! That!" exclaimed the sergeant. "What could you do? That was reported to the life-saving station hours ago. Best thing you can do is to help us track down the rascals who played such an inhuman trick on your friends."

"What could have been their motive?" demanded Mark suddenly.

"That," said the officer, "is a mystery which must be cleared up. We think we know. But you never can tell. Are you ready? We'll have a cup of coffee before we go."

A half hour later Mark found himself standing once more before the old scow. In the broad light of day it had lost much of its air of mystery.

The door had been left open and had been blown half full of snow. Having climbed over this pile of snow, they entered the hallway and descended the narrow, circular stairs.

A hasty search told them that the place was deserted. A careful examination revealed the fact that the bottom of the scow had been cut away; that a cellar had been dug beneath it, then walled up with cement.

"Regular underground den," the officer exclaimed. "Must have been a swarm of them."

"Twenty or thirty, I guess," said Mark absent-mindedly. He had picked up a clumsily hand-forged ax.

"Guess I'll take that along," he said presently.

In another room he found a large iron pot one-third full of a peculiar grease.

"That settles it," he murmured. "Come on over to my schooner."

They went to his schooner. A comparison of his sample of grease with that in the iron pot left no doubt as to who had greased the track over which the O Moo had glided to the water. The ax he had brought from the scow had a cross on one side of it, cut no doubt with a chisel when the steel was still hot. The cross embossed on the wood exactly fitted in the cross on the side of the ax.

"They drove the ax in to pull the nails," Mark explained. "Then when the cleats didn't give way, they used something to pry the ax loose. That's how the ax came to leave its mark."

"You'd have thought the noise would have wakened your friends," said the officer.

"There was a wild storm. Couldn't hear anything."

"Well," said the sergeant, yawning as he rose, "that fixes something definitely on them. That's what we've been trying to do for some time.

Next thing is to catch them."

"But why did they do it?" insisted Mark.

"Well," replied the sergeant, "since you've helped us and I know you won't go blabbing, I'll tell you what we think."

It was a long story, a story so absorbingly mysterious that Mark started when he looked at the clock and saw that a whole hour had been consumed in the telling of it.

"So that's that," smiled the officer as he rose to go. "Tell your lady friends on this O Moo if you like but not anybody else. They've got a right to know, I guess, and they'll keep quiet about it until the thing's settled for good and all."

CHAPTER XIII LAND AT LAST

Florence stood upon the deck. The storm had swept it clean. She was clinging to a hand rail at the side of the cabin. The water was still rolling about in great sweeping swells. Fog hung low over all. Strain her eyes as she might, she could see but a hundred yards. The boat, she discovered, had no horn or siren attached to it.

"If only we had one," she told Marian, "we could keep it going. Then, if anyone is searching for us, he would be able to locate us by the sound."

She stood there trying to imagine where they were, and what was to be the next scene in their little drama. All efforts to start the engine had been futile. There are a thousand types of gasoline engines. Marian had at one time managed a small motor on Lucile's boat but that one had been of quite a different type.

"'Tisn't any use," Marian had sighed at last. "We can't get it going."

So there Florence stood thinking. Marian was in the cabin preparing some hot soup for Lucile. Lucile's condition was much improved. She was sitting up in her berth. That much was good. But where were they and whither were they bound?

They had gone over their supplies and had found in all about eight pounds of flour and part of a tin of baking powder, three pounds of sugar, a half pound of coffee and a quarter pound of tea, two tins of sardines, a few dried prunes and peaches, two gla.s.ses of preserves and a few other odds and ends. Beside these there were still twelve cans of the "unlabeled and unknown" vegetables and fruit.

"I hope," Marian had smiled, "that they are all corn. One can live much longer on corn than on pineapple."

"But we can't live long on that supply," Florence had said soberly.

"Something has just got to happen. And," she had added, "perhaps it won't. If it were summer, things would be different, for at that time of the year the lake is dotted with vessels. But now they are all holed up or in dry dock. Only now and then one ventures out. We may have been blown out a long way from sh.o.r.e too; probably were."

She was thinking of all this now. At the same time her eyes were squinting, half closed. She was trying to pierce the fog.

Suddenly she started. Had she seen something off to the left? A whitish bulk rising out of the fog?

She could not be sure. Well aware that one's eyes play tricks on him when out at sea, she looked away, then turned her gaze once more to the left.

"Gone!" she muttered. "Never was there at all."

Again she struck that listless, drooping pose which gave her whole body rest.