“If only Harry could have been along to enjoy this wonderful triumph with us, or Dr. Perkins either. It would have completed our victory. But from here I can see that army on the move as plain as anything. They’re meaning to make one of their terrible drives somewhere along the Yser Canal, perhaps when that air raid comes off that we heard so much quiet talk about.”

“Well, that raid may be held up a while,” Frank told him. “They must believe that French or British pilots are aboard the Sea Eagle right now; and for all they know there are half a dozen just such big aircraft waiting to engage their fleet if it hove in sight of Dunkirk or Calais.”

“Every time we make a sweep around you can see the nearest Taube scuttle off in a big hurry,” ventured Billy. “Why, Frank, some of those machines are carrying a quick-firer with them, but they’ve had orders not to take risks. What would you do if they actually started to close in on us?”

Frank laughed as though that did not worry him very much.

“Why, there are several things we could do, Billy. In the first place we can go higher with the Sea Eagle than any of those flimsy Taubes would dare to venture, though I’d hate to risk it in this bitter cold air.”

“Yes, that’s true, Frank, and like you I hope we will not have to climb any further. It isn’t so bad in the summer, but excuse me from doing it now. We would need two more coats on top of the ones we’ve got, and another hood to keep our ears from being frozen stiff. What’s the other idea?”

“A straight run-away,” explained Frank. “If I really saw that any of them meant business, I could crack on all speed until we were making the entire two thousand revolutions per minute. That would leave them far behind.”

“I should think so,” admitted Billy, who had the greatest possible faith in the ability of the seaplane, as well as the cleverness of its young pilot. “Once we got to going our prettiest and they would look as if they might be standing still. Who’s afraid? Set ’em up in the other alley!”

“I think I’ll show them something to start them guessing,” Frank was saying a minute later. “They haven’t yet seen what she can do under forced pressure.”

“Let her out to the limit then,” pleaded the passenger, who could never experience too much excitement.