"you will empty the trench alone?"

"Not exactly alone," replied Tarzan with a grim smile; "but I shall
empty it, and, by the way, your men may come in through the tunnel
from the listening post if you prefer. In about half an hour,
Colonel," and he turned and left them.

As he passed through the camp there flashed suddenly upon the screen
of recollection, conjured there by some reminder of his previous
visit to headquarters, doubtless, the image of the officer he had
passed as he quit the colonel that other time and simultaneously
recognition of the face that had been revealed by the light from
the fire. He shook his head dubiously. No, it could not be and
yet the features of the young officer were identical with those of
Fraulein Kircher, the German spy he had seen at German headquarters
the night he took Major Schneider from under the nose of the Hun
general and his staff.

Beyond the last line of sentinels Tarzan moved quickly in the
direction of Numa, the lion. The beast was lying down as Tarzan
approached, but he rose as the ape-man reached his side. A low
whine escaped his muzzled lips. Tarzan smiled for he recognized in
the new note almost a supplication--it was more like the whine of
a hungry dog begging for food than the voice of the proud king of
beasts.

"Soon you will kill--and feed," he murmured in the vernacular of
the great apes.

He unfastened the rope from about the tree and, with Numa close
at his side, slunk into No Man's Land. There was little rifle fire
and only an occasional shell vouched for the presence of artillery
behind the opposing lines. As the shells from both sides were
falling well back of the trenches, they constituted no menace to
Tarzan; but the noise of them and that of the rifle fire had a marked
effect upon Numa who crouched, trembling, close to the Tarmangani
as though seeking protection.

Cautiously the two beasts moved forward toward the listening post
of the Germans. In one hand Tarzan carried the bomb the English had
given him, in the other was the coiled rope attached to the lion.
At last Tarzan could see the position a few yards ahead. His keen
eyes picked out the head and shoulders of the sentinel on watch.
The ape-man grasped the bomb firmly in his right hand. He measured
the distance with his eye and gathered his feet beneath him, then
in a single motion he rose and threw the missile, immediately
flattening himself prone upon the ground.

Five seconds later the