With lower jaw still drooping, Mike turned his head and stared at the speaker. He yearned to crush him with a suitable reply, but all his wit had been knocked out of him by the cruel blow of fate. However, it could not long remain so. He picked up the fragments of the potato, fumbled them reprovingly and gravely laid them on the tablecloth beside his plate. Then the old grin bisected his homely face, and addressing the three, he said:

"I made a slight mistake, as Jerry Sullivan said whin he stepped out of the third story windy thinking it was the top of the stairs. If it's all the same to yees, we'll now give our attintion to disposing of the remaining stuff on the boord."

Out of curiosity, the four cut in two each of the potatoes left in the dish. Every one was as sound as a dollar, whereat all laughed again, Mike as heartily as any.

"It'll be a sorry day whin I can't take a joke, as Jim Doolin said smiling whin his frinds pushed his cabin over on top of him as he lay sleeping behind it, but I was niver sarved such a trick before."

Chester thought the unanimous merriment caused by Mike's mishap would open an acquaintance between the lone guest and the others, but nothing more was said by the respective parties, nor did the watchfulness of the youth detect any further signals while at the table. Evidently an understanding had been brought about, and nothing else was required.

The meal finished, the four rose to leave the dining room. While there may have been nothing meant by Calvert's action in dropping to the rear, Chester was alert and glanced back as they walked into the hall outside.

He was rewarded by seeing the officer turn his head for an instant and give a slight nod. No doubt it was meant for the guest left behind, whose response was invisible to all except him for whom it was intended. The individual must have been blessed with a good appet.i.te, or he followed the sensible policy of lingering long over his meals, since he began eating before the little party and continued after their departure.

Reaching the pleasant, shady avenue, the four strolled through the town and when tired came back to the hotel and sat down. Chester was on the lookout for the stranger, but nothing was seen of him. What did it all mean and what was the cause of the secrecy between him and Stockham Calvert?

"If he chooses to explain I must wait until he is ready," was the decision of Chester.

The afternoon was well forward, when they walked down the slope to the wharf, where the _Deerfoot_ awaited them. Alvin made a hasty inspection of it and found everything seemingly all right. As they were about to step aboard, the officer said:

"I shall have to bid you good-by for awhile."

"Why is that?" asked the Captain, in surprise.

"You remember I told you it was likely, but I hope soon to meet you all again."

Nothing could be said by way of objection, and he stood on the wharf as Alvin seated himself after adjusting the plug and swinging over the fly-wheel. The boat circled out into the broad stream, and all waved their hands to the officer, who responded similarly. Then he turned about and went slowly up the slope, probably to the hotel where they had dined.

When everything was moving easily, and the boat was gliding down stream, Chester sitting directly beside his chum told him all that he had observed in the dining room. Mike had gone to the stern of the launch and sat down in his favorite position, with his feet curled up under him.

CHAPTER IX

A BREAK DOWN

Captain Alvin was keenly interested in the story of Chester Haynes. He admitted that he had noticed nothing peculiar, and it was evident that Mike had been equally blind to the events pa.s.sing under their eyes.

"It is plain," said Alvin, "that although Calvert told us a good many things about himself, there is a good deal more he didn't tell."

"What do you make of it all?"

"That man who was in the dining room with us may have been another detective or----"

"Or what?" asked Chester, observing the hesitation.

"I hate to say what comes into my mind, but every now and then a queer suspicion steals over me that Calvert is deceiving us and is not what he claims to be."

"In other words, he is a member of the gang whom he pretends to be hunting down."

"I am ashamed to confess it, but such has been my fear at times. And yet," the Captain hastened to add, as if regretting his unworthy thoughts, "it seems impossible, when we call to mind all he did and how he has acted from the first of our acquaintance with him."

Chester was thoughtful for a moment or two.

"I made up my mind after that rumpus down stream when he saved Mike from a bad beating, that he was just what he said, though I won't deny that more than one thing he has done--such as following us from Sawyer Island to the inlet where the _Water Witch_ lay, and his behavior on the road--had a queer look. But what's the use of speculating about it?

Sooner or later we shall know the truth, and, if we don't, I can't say I much care. Which course will you take in going home?"

"I haven't any choice; have you?"

"Suppose then you follow Back River, and around Cape Newagen home. That's a pretty good run, and at the rate we are going we sha'n't get there before dark."

"Have you any reason for the choice?"

"Only that we may catch sight of the _Water Witch_, from which we parted in those waters. If we do, we shall have to hold Mike in leash."

So it came about that the _Deerfoot_ turned into the headwaters of Back River, pa.s.sing Cushman Point through the Cowseagan Narrows, and into the more open waters below. Three or four miles farther would take them to Montsweag Bay, of which mention has been made, that body of water being twice or thrice as wide as the river.

Suddenly Chester asked an odd question:

"Do you think the launch was injured by that spurt this forenoon?"

"She ought not to have been, for she has gone through the strain more than once and for a longer time. Why do you ask?"

"Somehow or other, it seems to me she isn't running exactly right."

"What is wrong?"

"I can't put my finger on it; I may say I _feel_ it--that's all."

"Well, you are right, for I have had the same misgiving ever since we left Wisca.s.set. I have tried to figure it out, but can't and am waiting for it to develop, hoping all the time it won't--h.e.l.lo! there it comes!"

While the speed of the boat was not affected, the engine began hissing with vicious persistency.

"Take the wheel, Chester, while I look around."

He first examined the spark plugs, knowing that if one was broken the result would be what had just taken place, but all were intact. He had turned the switch, stopping the motor, and next inspected the valve caps where a fracture or loosening would have caused the hissing. They were sound and tight and the gaskets where the exhaust and intake pipes connected with the cylinders were tight.

"I've found it!" he called to Chester. "It's an open compression cup, which is easily fixed; I am glad it is nothing worse."

Remembering the lessons he had been taught, the young Captain soon corrected the fault and resumed progress. The launch, however, was held down to a comparatively slow pace, for the slight slip naturally caused misgiving. Several minutes pa.s.sed with all going well.

"It seems to me safe to give her more speed," said Chester. "At this rate we sha'n't reach home until late at night."

"All right; turn on more power--no, don't! _Ouch!_"

Alvin snapped his fingers, as one does when they are burned. He had placed them upon the exhaust pipe, which was growing red hot.

"Shut her off! The mischief is to pay."