Upon hearing the words uttered by the mechanic who handled the men working at their battleplane, Tom and his chum exchanged meaning looks.

“Can you make it perfectly safe again before half an hour passes?” asked the former anxiously.

“Surely,” came the confident reply.  “I know what’s in the wind, and you’ll be fit for any sort of flight when another fifteen minutes has gone by.  We’re on the last stay now, and I’ve carefully examined the motor and every other thing about the plane.  Don’t fear to risk your lives on my report.  I’d go up myself willingly if I had the chance.”

“All right, Sessions, we’re willing to take your word for it,” Tom assured him, and then drew his comrade aside.

Jack on his part was eager for a little talk between themselves.  That staggering fact had appalled, as well as angered, him.  Why should their particular plane have been selected for such treacherous work, among all the scores connected with the air service in that sector of the fighting front?

“What do you make of this thing, Tom?” he immediately demanded.

“It’s an ugly bit of business, I should say,” came the guarded reply.

“You mean calculated to make every one feel timid about taking any extraordinary risk—­is that it?” continued Jack.

“Yes, if the fact were generally circulated.  But according to my mind they’ll keep it quiet until after the armada gets off.  No use alarming the others, though orders have gone out I presume to have every plane carefully examined.  Still, that would only be ordinary caution; we never go up without doing such a thing.”

“Tom, do you think there could be any possible connection between this work of a German spy, as it appears on the surface, and my news from Mr. Smedley, the lawyer?”

“It’s possible—­even probable, Jack.  A whole lot depends on whether we learn of any other plane having been meddled with.  One thing sure, it’ll spur them to greater vigilance about watching things here.  This isn’t the first time there’s been a suspicion of rank treachery.  Planes have been known to be meddled with before now.”

“I wouldn’t put it past him!” muttered Jack sullenly.

“Meaning your cousin Randolph, I suppose,” Tom added.  “Nice opinion to have of a near relative, I must say.  But then I’m inclined to agree with you.  It may be only a queer coincidence, your getting such important news this afternoon, and some unknown party trying to bring about our downfall and death in this brazen way only a few hours afterwards.”

“And using corrosive acid, too,” spluttered the indignant Jack.  “I’ve heard of ropes being partly cut, even wire stays or struts filed to weaken them; but this is the limit.  Don’t I wish they’d caught the skunk in the act!”

“He’d never have left this aviation camp alive,” said Tom sternly.  “Why, the boys would be so furious they’d be tempted to lynch him offhand.”