The chief enemy, however, so far, was the biting cold. The thermometer was showing sixteen degrees below zero. Even with the thick leathern coats, pilots' boots and padded helmets, it was impossible to keep warm. The cold intruded everywhere. The thought which consoled them, however, was this: "We shall soon be there, now! And we shall be the first raiders to bomb the enemy's citadel, where he manufactures his enormous supply of shot and shell to keep the war going." They were following the Rhine still. Every now and then they could see long strings of barges being towed up and down the river between Coblentz and Dusseldorf. "Cologne!" shouted the observer, and Dastral nodded, as he looked ahead and saw the twin spires of the wonderful cathedral, and close beside it the ancient Rathaus. "What a target!" shouted Jock, as the great city lay beneath them. "Yes, but there are women and children down there, Jock, and I am not a pirate. When we get to Essen we will begin." "All right, old fellow. It was only a joke," came back the reply through the speaking-tube. They received another baptism of fire as they reached the outskirts of the city, but, skirting round to the right, they avoided the heavy fire of the forts at Deutz, for Dastral knew that the brutes were not shooting badly to-day, and he was anxious not to have a single machine crippled before his mission was completed. "There'll be plenty of fighting soon, my boy!" called Dastral. "The enemy will have guessed our objective by this time and they will be preparing a reception for us." The observer nodded, for he knew that the fires down below would be busy, and the various German Commands would be communicating with Essen and the arsenal at Krupps'. There was no time to lose, and so, despite the cold, they were still doing about one hundred and twenty miles an hour. "Dusseldorf!" soon came from the observer's nascelle, for they had passed Coblentz, and many other towns and villages that lay about the slopes of the Rhine. "See that!" shouted Jock. Dastral again looked in the direction pointed out by his comrade, and he beheld a great blur of smoke on the right, which blotted out the landscape. It was Germany's black country. Here the towns were clustered thickly together. Elberfeld, Barmen, Essen, and to the west of the last-mentioned town lay the mighty works of Krupps. Somewhere in that cloud of smoke lay the object of their long flight. The Flight-Commander pointed his machine in the direction indicated, and the rest followed. The real fight was about to begin at last. How would they come out of it? They were all eager to begin, for each machine carried a couple of the new land torpedoes, in addition to a number of twenty pound bombs.