"Well, we went over them; but it wouldn't do any harm to refresh my memory. You're to be in general charge of the navigation of the plane, and I'm to see to dropping the bombs—is that it?"

"That's it. You'll have to use your best judgment when it comes to your share. I'll get you over the German works and railroad centers, as nearly as I can in the dark, and then it will be up to you."

"I hope I don't fail," said Jack, speaking through the tube.

"You won't. Don't get nervous. Any kind of a hit will throw a scare into the Huns, and make them feel that they aren't the only ones who can make air raids. But in this case we're not bombing a defenseless town, and killing women and children. This is a fortified place we're going over, and it's well defended."

"Some difference," agreed Jack.

"And if we can get some direct hits," went on Tom, "and blow to smithereens some of their munition or armament factories, we'll be so much nearer to winning the war."

And that, in brief, was the object of the flight over the Rhine.

Once more the boys fell silent.

On and on swept the planes. Whether the Germans beneath were aware of the danger that menaced them, it is impossible to say. But they made no attempt to fire on the Italian craft. Probably because of the darkness, and owing to the great height at which they flew, the Huns were in ignorance of what was taking place.

On and on in the night and beneath the silent stars they flew. Now Tom and the pilot began watching for some landmark—some cluster of lights which would tell them their objective was within sight. But for another hour nothing was done save to guide the big craft steadily onward.