came upon it by chance to-night, and it saved my life. They seized me
to-night when I was in conference with them--the treacherous hounds! But
they are Servians! I might have expected it! I escaped, and they chased
me! They chased me right into the Danube! I swam, while they peppered
the water. They had those new silencers, so that it was safe to shoot.
And by the merest chance, when I was nearly exhausted, I suddenly saw a
door in front of me, as I was trying to swim ashore in an inlet, in the
hope of escaping after I had landed. I dived, and came up in a
boathouse. The door could be raised, you see, to admit a boat. There
was a closet, and I hid."

"That is news to me! I never heard that there was such a place!"

"I drew the closet door to when I heard a man come in. Soon afterward a
motor boat entered, and two men landed from her. I could hear their
voices dully--that closet door was thick, and it was so hot and close
inside that I was almost suffocated. I do not know who they were except
that I think Vanya, the soldier, was the man who opened for them. Later,
when they had gone, I got out and came here."

"It is good that you came. Master, it is to-night that they plan to
strike a great blow. They have dug a tunnel beneath the arsenal. I am
almost sure that it is to-night they have chosen to explode a great mine
that will destroy the arsenal completely, with all the stores and guns
it contains!"

Hallo swore savagely.

"You have done well!" he said. "Eh, there is time yet, you think, to
stop them? How is it that you do not know more concerning their plans?"

"They do not trust me wholly. I know only what I can learn by spying and
ferreting about. They tell me almost nothing. But I am sure that I am
right. Look--I will draw you a plan that will show you where the tunnel
is. I think that if you hasten you can catch most of them like rats in a
trap. Milikoff is not there. He is the most dangerous of all, save one."

"Who is more dangerous than Milikoff?"

"The boy Stepan Dushan!"

"Stepan Dushan! I do not believe there is such a boy! You tell me of
him, but you can never show him to me!"

For a moment Dick could not understand. But then he smiled at his own
stupidity. Of course Steve was known to Mike Hallo under an assumed
name; he would never have used his own, so obviously that of a Servian.

"It makes no difference whether you believe me or not, I am telling you
the truth," said the newcomer with a show