"But suppose the villain comes between spells?"
"We'll have to take our chances on that," said John.
The proposed scheme was finally accepted. About six o'clock Sam returned with the Black Growler and when the plan was explained to him he readily consented to accept the part which had been assigned to him.
That night at eleven o 'clock he called Fred who was to have the first watch. After the first half-hour the young guard in the silence that rested over the great river found the time dragging heavily. In order to keep awake he walked about the dock, peering intently in every direction. Not a sign of danger had been discovered, however, when at half-past twelve he summoned Grant to take his place.
Grant also was not molested and when he called George at two o'clock he said sleepily, "It all seems like fool business anyway, Pop."
"You've been asleep," retorted George.
"I haven't closed my eyes," retorted Grant sharply. "If you do as well you'll be lucky."
A half-hour after George had entered upon his task he stopped and peered through the window into the boathouse. The light of the moon made many of the objects within clear and distinct. The Black Growler was lying peacefully in her slip. Apparently peril was nowhere threatening.
Suddenly, as George glanced at the farther end of the platform beside the slip, he stopped abruptly and stepped quickly back from the window. Approaching the place again, he cautiously peered within and his first impressions were confirmed. He was able to see distinctly the figure of a man crouching in a corner of the room.
Instantly George's heart was thumping wildly and he was tempted to shout to the intruder. Hastily banishing the impulse he watched the man. The dim outline of his figure was distinctly seen. Perhaps the intruder had been startled by the discovery of the face at the window. At all events he remained motionless and not a sound was heard save the lapping of the little waves against the dock.