st who it
is."

"What is he doing here?" demanded John.

"I can't tell you," said Fred.

"Was he expected this morning?"

"Not to my knowledge."

When the boys went up the steps, however, Mr. Button summoned all four
to come to the place where he was seated.

Somewhat startled by the invitation the boys approached, all glancing
in some confusion at the man seated near Mr. Button. He was dressed in
a different suit now and many of his ways and manners had been changed
for the better. He was now at his ease and the twinkle that appeared in
his eyes was far different from the expression which the boys had seen
there in their earlier experiences with the man.

"You appear to be acquainted with this man," suggested Mr. Button dryly.

"We have seen him before," said George.

"And not exactly where you wanted to see him, I fancy," laughed Mr.
Button. "Do you know who he is?"

"No, sir," said George quickly, "and we don't know what he is either."

"Well, this is Mr. Brown from Syracuse," explained Mr. Button. "A gang
of bank robbers got into one of the vaults there some time ago and got
away with a large number of bonds. Mr. Brown was detailed to find and
catch the thieves if possible."

As Mr. Button ceased speaking the interest and excitement of the boys
at once increased.

They looked eagerly at one another and at Mr. Brown, who now assumed an
importance in their eyes, which before he had not had, even when they
believed him to be a false claimant to the bond which they had found on
board the Black Growler.

"Are you a detective?" inquired John, turning to Mr. Brown as he spoke.

"I don't speak of myself in that way," replied Mr. Brown, "and yet--"

"That's what he is," interrupted Mr. Button "He already has run down
and found most of the bonds."

"How did that one come to be on our boat?" inquired Grant.

"Why, I had it in my pocket," laughed Mr. Brown, "and I put it under
the cushion for safe keeping. You see, I joined that crowd and they
thought I was one of the canal-men. I was with them for ten days at
least and finally I found out what I wanted to know."

"Were they the bank thieves?" asked George eagerly.

"Some of them," replied Mr. Brown. "They were strangely mixed up. In
fact that is one of the tricks they have, I am told. When a bank is
broken into if the men are successful they scatter so that no two are
in the same locality. It took me a long time to get in with these men
but I finally