They set off at
once.

The island was a quarter of a mile across at its widest point. Even if
the whole party entered on the search they would have difficulty in
making so strong a human barrier across the isle that a fugitive in
the covert could not escape through the line.

But Chet occasionally had a bright idea as well as his sister. He sent
Short and Long--who could climb like a squirrel--to the top of a tall
tree on the knoll. From that height he could see every opening in the
wood, to the upper point of the island--which was nearly two miles
long.

"Now we'll all go and beat up the brush and see if we can start
anything bigger than a rabbit," Chet declared. "Spread out and try to
push through the woods as straight as possible."

"We girls, too?" cried Nellie.

"Be a sport, Nell, and come along," urged Jess Morse. "We'll be in
sight and call of each other all the time."

Which was true enough, as they soon discovered. Lil said it was her
turn to help do the camp work. And of course neither Mrs. Morse nor
Liz could go.

"Don't you think," Purt asked, seriously, "that one of us ought to
remain here and defend--er--the camp?"

"Sure," said Chet, quickly. "We'll leave Art, if you say so. He rather
admires Lil, too, Purt."

This made the dude keep still; but he _did_ dislike this "manhunt" in
the thick brush of Acorn Island.

After they had gone half a mile or so, and found nothing--not even a
trace of anybody else having camped on the island--they all took the
situation more cheerfully. They believed whoever had stolen the girls'
food had already departed.

"Some of these fancy city fishermen, like enough," Chet declared, when
they all came together at the western point of the island. "See
yonder! there are two men in a boat, fishing, now."

"If they were the robbers they would not boldly anchor off there," his
sister said.

"True enough, Laura," said Bobby. "I believe that whoever stole from
us, is far away now. And everybody who comes to the lake knows that it
is forbidden to camp on Acorn Island. The guides all know it."

"How about what Liz says about the man she saw last evening?" demanded
Jess. "She says he was a man she knew in Albany."

"She had been talking to me about him," laughed Laura, "and I guess he
was in her mind. Why should such a man come and rob our camp?"

"Well! it's a mystery," Chet said. "But I reckon you'll not be
bothered again; the island seems empty save for ourselves.