iscovered the first clue--a huge human-like
footprint in the soft earth beside the spring, and indications of a
struggle in the mud.

Then I found a tiny handkerchief close to the outer wall. Lys had been
stolen! It was all too plain. Some hideous member of the ape-man
tribe had entered the fort and carried her off. While I stood stunned
and horrified at the frightful evidence before me, there came from the
direction of the great lake an increasing sound that rose to the volume
of a shriek. We all looked up as the noise approached apparently just
above us, and a moment later there followed a terrific explosion which
hurled us to the ground. When we clambered to our feet, we saw a large
section of the west wall torn and shattered. It was Olson who first
recovered from his daze sufficiently to guess the explanation of the
phenomenon.

"A shell!" he cried. "And there ain't no shells in Caspak besides
what's on the U-33. The dirty boches are shellin' the fort. Come on!"
And he grasped his rifle and started on a run toward the lake. It was
over two miles, but we did not pause until the harbor was in view, and
still we could not see the lake because of the sandstone cliffs which
intervened. We ran as fast as we could around the lower end of the
harbor, scrambled up the cliffs and at last stood upon their summit in
full view of the lake. Far away down the coast, toward the river
through which we had come to reach the lake, we saw upon the surface
the outline of the U-33, black smoke vomiting from her funnel.

Von Schoenvorts had succeeded in refining the oil! The cur had broken
his every pledge and was leaving us there to our fates. He had even
shelled the fort as a parting compliment; nor could anything have been
more truly Prussian than this leave-taking of the Baron Friedrich von
Schoenvorts.

Olson, Whitely, Wilson, and I stood for a moment looking at one
another. It seemed incredible that man could be so perfidious--that we
had really seen with our own eyes the thing that we had seen; but when
we returned to the fort, the shattered wall gave us ample evidence that
there was no mistake.

Then we began to speculate as to whether it had been an ape-man or a
Prussian that had abducted Lys. From what we knew of von Schoenvorts,
we would not have been surprised at anything from him; but the
footprints by the spring seemed indisputable evidence that one of
Caprona's undeveloped men had borne off the girl I lo