all
through my own fault," went on the Spaniard, dramatically. "As
soon as I met you boys, after you had saved my life, I repented of
my part, but I could not withdraw. The plans of this scoundrel
--yes, I must call him so, though perhaps I am as great--his
plans called for finding out something about the big guns that
protect the Canal. Only I was not able to do that, though he
ordered me to in a letter I think you saw."

Blake nodded. He and Joe were beginning to understand many strange
things.

"One of the secret agents brought me the box containing the
mechanism that was to set off the dynamite," the Spaniard resumed.
"You nearly caught him," he added, and Blake recalled the episode
of the cigar smoke. "I had secret conferences with the men engaged
with me in the plot," the conspirator confessed. "At times I
talked freely about dynamiting the dam, in order to throw off the
suspicions I saw you entertained regarding me. But I must explain
one thing. The collision, in which the tug was sunk, had nothing
to do with the plot. That was a simple accident, though I did know
the captain of that unlucky steamer.

"Finally, after I had absented myself from here several times, to
see that all the details of the plot were arranged, I received a
letter telling me the dynamite had been placed, and that, after I
had set it off, I had better flee to Europe."

Blake had accidentally seen that letter.

"I received instructions, the time we were starting off on the
tug," went on Alcando, "that the original plot was to be changed,
and that a big charge of dynamite was to be used instead of a
small one.

"But I refused to agree to it," he declared. "I felt that, in
spite of what I might do to implicate myself, you boys would be
blamed, and I could not have that if the Canal were to suffer
great damage. I would have done anything to protect you, after
what you did in saving my worthless life," he said bitterly. "So I
would not agree to all the plans of that scoundrel, though he
urged me most hotly.

"But it is all over, now!" he exclaimed with a tragic gesture. "I
am caught, and it serves me right. Only I can be blamed. My good
friends, you will not be," and he smiled at Blake and Joe. "I am
glad all the suspense is at an end. I deserve my punishment. I did
not know the plot had been discovered, and that the stage was set
to make so brilliant a capture of me. But I am glad you boys had
the honor.

"But please believe me in