Part 18 (1/2)

”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.