Quickly withdrawing, Grant took his place and silently peered into the
slip. At the same time John and Fred were making their investigations
on the opposite side of the slip, although Fred was having his
difficulties because he was not tall enough to enable him to look
through the glass.

The man whom George had discovered apparently had not moved from the
place in which he had first been seen. Perhaps he too was listening and
was fearful of an attack.

Their excitement now greatly intensified, George beckoned for John and
Fred to come to the place where he and Grant were standing on the dock.

"He's there," whispered Fred.

"I told you he was," whispered George in reply. "Now the question is
how shall we get him?"

"How did he get in?" inquired Grant.

"I don't know," replied George, shaking his head. "There isn't any
window open and the doors are locked."

"He must have dived under the door and come up that way," suggested
John.

"This isn't any time to be discussing how he got there," remarked
George. "The thing for us to do is to find out how we are going to get
him out or get him. Let's go around to the window on the river side."

In response to the suggestion the boys stealthily crept along the dock
and then one after another cautiously peered through the window. Not
one of them stood in full view of the man within, for they were aware
of the peril that might follow such an action.

"He's still there," whispered Fred, "and I don't believe he has moved
once since we came back."

"He's scared," suggested John. "He doesn't know which way to turn."

The suggestion that the intruder might be alarmed was new to the Go
Ahead boys and did much to revive their courage.

John and George each had secured a bat when they had left the house.
And now they were prepared to defend the motor-boat and themselves also
if the need arose.

"Knock on the window," suggested Grant. "Let the fellow know we're
here."

"He may get away," warned George, who still was the most excited of all.

"If he tries to, we'll get him then anyway," said Grant. "Go around and
look on the other side of the boat-house," he directed Fred and John.
"We'll wait here. I'll rap on the window and we'll see what he does."

Grant waited until sufficient time had elapsed to enable his friends to
take their position in front of the entrance on the opposite side and
then rapped lightly upon the window. No response was made to his
summons.

"