Ahead of this loomed two hills. They rose abruptly, treeless and precipitous. On the one nearest to the German lines was a ruined tower.

"The tower," said the officer, "would have been a charming place for luncheon. But the hill has been shelled steadily for several days. I have no idea why the Germans are shelling it. There is nobody there."

CHAPTER XXX

THE MILITARY SECRET

The second hill was our destination. At the foot of it the car stopped and we got out. A steep path with here and there a wooden step led to the summit. At the foot of the path was a sentry and behind him one of the multicoloured tents.

"Are you a good climber?" asked the officer.

I said I was and we set out. The path extended only a part of the way, to a place perhaps two hundred feet beyond the road, where what we would call a cyclone cellar in America had been dug out of the hillside. Like the others of the sort I had seen, it was muddy and uninviting, practically a cave with a roof of turf.

The path ceased, and it was necessary to go diagonally up the steep hillside through the snow. From numberless guns at the base of the hill came steady reports, and as we ascended it was explained to me that I was about to visit the headquarters of Major General H——, commanding an army division.

"The last person I brought here," said the young officer, smiling, "was the Prince of Wales."

We reached the top at last. There was a tiny farmhouse, a low stable with a thatched roof, and, towering over all, the arms of a great windmill. Chickens cackled round my feet, a pig grunted in a corner, and apparently from directly underneath came the ear-splitting reports of a battery as it fired.