Tom gave a sigh of relief when that part of the proceeding was finished. He had entertained a little fear that Jack, in his haste to get things over with, might spill the precious fluid on which so much depended.

Afterwards Tom examined for himself, and was satisfied.

"Not a sign of a leak yet, and there isn't going to be either," he told his companion, not exultantly, but nevertheless with confidence that a belief in the staying qualities of his own work justified.

"Now we can get going on the second part of our programme," Jack returned, as he once more cast a steady look toward the height on which the chateau stood.

"No need of staying here another minute, Jack. Nobody knows just what's going on over there, or how long those visitors mean to stay."

"All the same," the other air service boy mentioned, as if casually, "General von Berthold is giving his guests a regular jolly time of it. In these days of war I reckon the Huns are missing pretty much all their favorite drinks, and when they do strike a cellar full—and I guess they have it here—it's like drawing teeth to pry them loose. Listen, don't you hear them at it now?"

Indeed, it would have been impossible for any one with ordinary hearing, when within half a mile of the chateau, not to have heard what Jack referred to. Some one was singing at the top of his voice, and a heavy voice he had in the bargain. He kept time with the rhythm of his song by repeated poundings on a table with what might have been a stein.

"Well, what nerve!" ejaculated Jack. "It's the Watch on the Rhine he's trolling, as sure as you live!"

"And with the whole bunch joining in the chorus in the bargain," added Tom, as the burst of singing suddenly grew stronger in volume. "They utterly refuse to believe they're whipped flat, even with the Americans ready to step over into Germany and mop 'em up all the way to Berlin."

"Huh!" snorted Jack disdainfully, "we'll soon be the ones keeping watch on the Rhine, see if we'll not. Only sillies with their wits flabbergasted by pride would shut their eyes to the handwriting on the wall. But I'm not sorry, for if they keep on enjoying themselves in that way we'll find it an easy job to roam all over the old shack, looking for Helene."