try to stop him if he had gone into a house,
and the place might not have been so quiet and deserted as the one he
chose."

Dick went on to tell of the strange walk that he and Hallo had taken,
and Steve laughed heartily. But his face was grave when Dick had
finished.

"It seems trifling enough now," he said, "but it was no laughing matter,
Dick. You were in terrible danger all the time, of course, and anyone
less cool and clear headed would never have come through so well. Having
Hallo gives us a breathing spell. We may be able to use the boathouse
still. If he had got away, even after the arsenal was blown up, we could
never have used it. We may not have to. I think most of our work here in
Semlin was finished to-night. Soon the armies in the field will be doing
the work, and the time for the spies will have passed."

At the boathouse Milikoff joined them, his face glowing.

"All here? Not a man lost? That makes it so much the better!" he
exclaimed, happily. "And--what? You have Hallo again? Welcome back,
Hallo! This is splendid!"

"I think we had better get away," said Stepan. "After this business
to-night, there will be a most searching examination, and it would be
dangerous for any of us to stay here. We cannot carry many in the motor
boat, but there will be time for her to make three trips, and that will
be enough. I shall run her back first, and take my friend Dick Warner
and Hallo. One other can come. You, Milikoff?"

"No. I shall go on the last trip," said Milikoff. "Let one of the men
bring her back. It will be your part to see that Hallo is looked after
in Belgrade."

So they ventured out into the yellow Danube again. This time the voyage
promised to be more dangerous. The destruction of the arsenal had
aroused all the forces defending Semlin to a high pitch, and
searchlights danced incessantly about, winking first one way, then
another. There was still a blaze of light at the confluence of the Save
and the Danube, but more searchlights seemed to be in use, and the
Austrians were not as perfunctory as they had been, but flashed them
here, there, and anywhere.

However, Steve was a skillful handler of the swift little craft. Darting
forward when the flashing of a light left a space dark, turning this way
and that, coming almost to a full stop when the river ahead was suddenly
lighted, he played hide and seek amid the great, flashing beams of
light. And at last they were well beyond them, and could s