We did not quite understand Oakes's speech, but there evidently was something behind it.

At this point, with his characteristic swiftness of movement, he lighted a cigar and began to smoke, offering the box to us all.

That meant that, as far as he was concerned, talking on business had ceased for a time. He was now recreating.

Elliott and I walked to a window and looked out upon the front walk and the road, conversing upon the manner in which Joe had been brought to Mona.

He had resisted the idea at first, but through the efforts of Martin and Elliott, and the promise of a reward, he had finally consented to the journey. They had explained to him that his refusal would defeat the ends of justice, and that escape was impossible; and when he realized that he had been unconsciously talking to watchers, and polishing their shoes in his innocence, he saw the folly of further remonstrance. Thus was the important evidence of the negro secured.

The strain of events was telling on us all. Quintus Oakes showed his deep concern by a tendency to leave us and remain alone.

As Elliott and I were talking, he looked at the rolling hills beyond the pond and exclaimed:

"Look! Can I be mistaken, Mr. Stone? Look in the direction of Mona--away off on the plateau--is not that a horse?"

I followed his pointing and discovered in the moonlight the figure of a horse advancing rapidly over the blue-green fields, along the path that led to the bridge.

Oakes advanced to the window and gazed intently, shading his eyes with his hands. On the crest of the hill that dipped to the pond the horse soon stood out clearly against the dark blue of the sky. We could see a figure which had lain low on his neck rise and sit straight in the saddle, then flash a light.

From near the road, on our side of the pond, came an answering light; a man stood there and exchanged signals with the horseman.

The rider was moving his arms rapidly, and with them the light. The other was answering in a similar manner.

Oakes remained quiet, and we all gathered at the window about him.

"What is it?" I asked.

He turned and said to me: "Here, write as I read."

I took an envelope and pencil from my pocket and wrote as Oakes deciphered the signals.

"A message from Mona," he cried. "Quick!"

Then he read the letters as they appeared:

"Discovered. Skinner has extra out. p.r.o.nounces me false; says Hallen has tricked the town. Beware of Skinner. Tell Hallen to look out. Am off for New York."

Then came a long wave over the head, and the horseman dashed back toward Lorona.

We detected another horseman at a little distance, who joined him; they rapidly disappeared together.

"Excellent!" exclaimed Oakes. "He has done his duty well."

We saw the man on this side run post haste for the Mansion. As he rushed up the steps, Oakes met him. "All right, boy! I saw the signals myself."

Then to us he said: "Quintus Oakes the false is discovered. That was he; he came to warn us."

"Then Skinner has caught on, confound him," said Dowd, and we all silently a.s.sented.

Oakes paced the room slowly. "Boys, we have been unexpectedly checked.

The enemy has a strong hand: there is trouble ahead."

"Yes, there is that," retorted the vigorous Hallen. "I must get away to headquarters, gentlemen!"

"Correct!" answered Oakes; "and we will go with you, Chief. If trouble is coming, we will be useless here."

With one accord we prepared to depart for Mona immediately. The carriage was brought to the door and saddle-horses also.

Then we waited anxiously for the return of Martin's party. We were not long delayed. A commotion in the hall was heard, and in stepped Joe and Martin, followed by the men. Oakes's a.s.sistant advanced and laid a red handkerchief, dotted with white spots, upon the table. It was wet and heavy, and knotted by its four corners so as to form a pouch.

"We found it, sir, in about two feet of water, partly covered with sand.

Its weight was gradually sinking it into the bottom."

Joe laughed hysterically and lapsed into negro dialect: "See, Mars Oakes! see, boss! I dun tole you the truth."

Oakes seized the handkerchief, and we all looked inside. It contained a few large cartridges.

"They match the one I found in the cellar, and those of the old revolver," said Oakes. "The man of the Mansion mysteries and a.s.saults _is_ the murderer of Mr. Mark."

We were intensely excited as we stood there viewing the evidence that was so conclusive. Not one of us made a remark, but the deep breathing of some and the pale faces of others showed the interest that was felt by one and all.

Oakes discovered on one end of the handkerchief the initial "S," and we all studied its appearance closely. Then Oakes asked Hallen if such handkerchiefs were unusual in Mona.

"No, not at all; there are hundreds of them sold here, especially to the laborers on the water-works--the Italians and Poles," answered the Chief.

"It is a very peculiar 'S,'" said Oakes, as he folded the handkerchief and put it in his pocket, giving the cartridges to Martin. He said nothing more, but seemed serious and thoughtful, as usual. And then we set out all together on a wild drive to police headquarters.

Despite the lateness of the hour, the crowds were increasing. The square, with the hotel on one side and headquarters on the other, was the centre of a vicious body of men, pushing, struggling and forcing its way along, and pausing now and again to surge around headquarters. We could all see that Hallen was to have his hands full.

"I should like to see Skinner very much," remarked Oakes in a sarcastic vein.

"I should like to see his arms," said Moore; "they might be interesting."

Oakes looked at the speaker with one of his undefinable expressions. We could not tell whether the shot had been a true one or not.

_CHAPTER XVIII_

_Misadventures_

Toward morning the crowd thinned. The street grew more quiet, although the very air still throbbed with action, even as the heart-strokes within us. Quickly as events had come, we were yet only in the midst of our experiences.

The clock in the Chief's room was striking three, and drowsiness was stealing over me, as over the outside world, when a knock came at the front door and Hallen admitted a man, weary-eyed and panting. I recognized him as one of the men who had been masquerading about the Mansion as a carpenter. He was dressed in a heavy jersey without a coat, and was evidently suffering from fatigue.