In the minds of each of the young people in the canoes, one word kept repeating itself over and over again: "Spy, spy, spy!"

Since the war had begun, the country had been overrun with them, that they knew; but out here on this remote island… Yet there was something about the very posture of the man, his hunched-up figure, the nervous twitching of the fingers that held the document, that branded him.

As they watched, he started to fold up the paper, glancing stealthily about meanwhile; then, as though satisfied that no one was watching, he picked up the heavy bag that lay beside him, evidently preparing for flight.

Betty, a little tense figure in the bottom of the boat, uttered a gasp of dismay, as Allen began carefully to lower himself into the shallow water.

The man on shore heard the slight sound and turned swiftly, staring suspiciously into the thick shadows of the foliage. Then did the boys and girls literally hold their breath.

After a few seconds, which seemed an eternity to the taut nerves of the watchers, the man turned with a guttural growl, and started cautiously to make off into the denser woodland beyond.

In a second, Allen was out of the boat, and lending a hand to the gallant Little Captain, who would not be outdone in any adventure, no matter how perilous.

The other boys and girls followed, silent as ghosts, their training in woodcraft standing them in good stead. For an instant, they stood in a tense, excited group on shore, Mrs. Irving in their midst.

"I'll tell you what we'll do," Allen was saying, and they had to lean close to catch the words, which were barely above a whisper. "There must be a guard around this mill somewhere. We'll get him, and head that fellow off."

"I'll take you to a guard," said Will suddenly. "We'll find him at the other end of the mill."