tch in the rapidly fading light.

"For some reason observer and pilot sit back to back," said Laval. "But
you can slue your seat round and work your gun from the right if you
like. You will find everything ready for use, signalling lamp and a fine
map." And with a blue pencil he marked off the course they were about to
take and the various landmarks, for which a sharp look out must be kept.

Then the whir of machinery cut off all possibility of further
conversation; Dennis gazed round at the darkening landscape as Laval
released her, and after a short run forward over the grassland the
Aviatik began to rise.

So far, Dennis had not counted the cost of his adventurous expedition,
or the by no means remote possibilities of his being captured and sent
to terrible Ruhleben. He had only seen the dash and daring of it all,
and now he could only see the velvety blackness that lay thousands of
feet beneath, where the earth was.

Once from very far below them the boom of guns made itself heard, even
above the flogging of the engines and the whir of the tractor in front
of him, and his pilot handed back a scrap of paper on which he had
scrawled some words.

Switching on his torch Dennis read: "We are crossing our own lines now.
That light away to my left is Metz. We are over Lorraine, and I am going
to turn south-east."

Through his glasses Dennis could see a dull glow in the distance, which
was soon left behind as Laval altered the course, and for some time
their flight was through cloud-banks which hid everything.

After a while the pilot passed him another message. "Look down; we
cannot be far from the Rhine now, and it is important to know when we
cross it. Keep a sharp look out."

The depression of the point of the _nacelle_ told Dennis that the
Aviatik was planing down to a lower altitude, and when, some distance
ahead, he saw the milky gleam of a river winding away to right and left,
he hung over the side with the powerful German glasses glued to his
eyes.

The moment it passed beneath them he touched Laval on the shoulder, and,
swinging round again to the right, they flew almost due south, still
coming down lower and lower.

It was a clear night, and the visible difference in the blackness of the
ground here and there told Dennis that they were traversing above
mountainous country, while the little bright specks shining like
glow-worms marked the existence of enemy towns and villages, whose
inhabitants fancie