"I've got an idea," cried Whopper. "Why not fix it so as to give them a warm reception---if they do come," and then he explained what he meant.

In the end it was decided that Snap and Shep should remain at the boathouse, and Whopper ran off to tell their folks and to get a few things. As the boys were used to outings the youths' parents thought little of their staying away that night, and only sent word back that they should keep out of mischief.

"We'll keep out if we are left alone," said the doctor's son, grimly.

Whopper had brought with him an old tin pail containing some hot water and half a pound of flour. This was stirred up into a thick flour paste, and to give it the "proper flavor," as Snap suggested, they broke into the mixture two ancient eggs which one of the party had picked up.

Joe Bright had been sent away, with instructions to say nothing about what was going on at the boathouse, and soon Whopper followed him. Then Snap and Shep went into the building and locked the door behind them.

The structure was a one-story affair, with a small loft overhead, for the storage of extra oars and odds and ends of boat lumber.

Up into the loft went the two boys and opened the tiny window at either end---thus letting in some needed fresh air. Then they took the rank-smelling flour paste and poured half of the stuff into an old paint can that was handy.

"Let us take turns at resting," suggested Snap, and so it was arranged.

It was a calm, clear night and before long the town was wrapped in slumber, and only the occasional bark of a dog or yowl of a cat broke the stillness. Out on the river nothing was stirring.

It was after midnight, and Snap had almost reached the conclusion that the alarm had been a false one, when, looking from one of the little windows, he saw two figures approaching the boathouse. The two boys or men had their coat collars turned up and their soft hats pulled well down over their foreheads.

Making no noise Snap aroused Shep, who was sound asleep on the cot.

"What is it?" demanded the doctor's son.

"They are coming. Hush, or they may hear you."

Silently the two boys crawled to the small window facing the town.

The two figures outside were now close by and Snap and Shep felt sure they, were Ham and Carl.

"Anybody around?" came the question, in a whisper.

"I don't see anybody."

"We don't want to get caught at this."

"Oh, don't get chicken-hearted, Carl."

"Humph! Please remember what happened last winter, Ham."

"Hush! Don't speak my name, please."

"Well, then don't speak mine."

"I didn't."

"Yes, you did."

"I did not, I say. Come on."

"How are you going to get in? You said you knew of a way. I am certain the doors and windows are all tight."

"Just you follow me and I'll show you a nice little trick."

"But where do you want me to follow you to?" insisted Carl Dudder.

"Under the boathouse."

"Under it?"

"Yes. Here is a place where we can crawl under very easily."

"Yes, but what are you going to do after you are under the building?"

"Get inside."

"Is there a trap door?"

"No, but I know where a couple of boards are loose in the flooring, and we can shove them up easily."

"Oh! All right, go ahead, and I'll follow."

A moment later Ham Spink let himself down in a little hole beside the boathouse. Here his feet were close to the water, but he supported himself on a cross rail nailed from one section of the spiling to another. Carl Dudder followed him, and both moved cautiously forward to the front end of the building. Once Ham slipped and a slight splash followed.

"What's that?" cried Carl, in alarm, for he was decidedly nervous.

"My foot slipped, that's all," was the answer.

"Is it deep under here?

"Not over four or five feet."

"Where are those loose boards?"

"Right here. Now take hold of that end and we'll soon have them up and be inside the building," answered Ham.

CHAPTER VIII

HOW TWO PROWLERS WERE TREATED

While Ham and Carl were moving around under the boathouse, Shep and Snap were not idle. The doctor's son, on awakening, had wanted to throw the flour paste out of the window at the midnight prowlers, but Snap thought of another plan.

"Come on below, and wait until they shove up the flooring," he whispered.

The doctor's son understood, and with caution, so as not to make any noise, the two chums came down out of the tiny loft, bringing with them the pail and the tin can of awful-smelling flour paste.

It was absolutely dark below, but they could plainly hear Ham and Carl working on the loose boards of the floor near the river end of the boathouse. Thither they made their way, Snap with the pail and Shep with the can, both ready for action.