"Some Hun officer stole our airplane," said Bob. "That's what I make of it."

"But the war is over," protested Frank.

"Maybe it is," said Bob darkly. "But if that bird doesn't fly back with our airplane I'll make war on Germany myself."

Despite his gloom, Frank grinned. He slapped big Bob on the back.

"Come on, old boy," he said. "No use hanging around here. We may as well go back to the house and report the latest mystery."

"I wonder," said Bob, as they set out, "whether there is any connection between the two--between this theft of our airplane and that stuff yesterday."

It was Mr. Temple who was able to provide an answer to that question.

The boys found him up and dressed when they reached home, and himself considerably excited over a telephone call from New York City. He, too, was dismayed when told of the theft of the airplane. But when the boys showed him the German Iron Cross he hit the desk before him a resounding blow with his fist. Their conversation took place in the library.

"That fits right into the puzzle," said he. "Boys, while you were out of the house I had a long distance telephone call from New York City.

The man who called said he was a chauffeur who had driven two men down here yesterday, that he thought they were on legitimate business, but that when Bob tried to stop them he saw they were bad ones, as he put it. Later, when they made him drive them over to the radiophone station and he heard Tom rout them with his pistol shots, he said he drove off as they ran for his car and left them. He inquired in the village and learned my name, and so called me up to clear himself in case I intended starting a pursuit.

"And he said," added Mr. Temple, leaning forward and speaking impressively, "that he was pretty certain one man was a Greaser and the other a Hun. Those were his own words. Of course, he meant one was a Mexican and the other a German."

"So when this chauffeur abandoned them they stole our airplane to get away," cried Frank excitedly.

"Exactly."

"Maybe," said Bob, "I copped every cent they had in pulling that Mexican's coat off his back, and they were without carfare back to the city."

"Oh, I suppose the German had money," said his father. "The German probably was an aviator. And they stole the airplane in order to escape from here quickly before we could get in pursuit of them. I imagine they'll land in some deserted spot--plenty of them in the sandy reaches along the New Jersey coast, for instance--make their way to a railroad, after abandoning the plane, and go----"

"To the Southwest," said Frank, emphatically, interrupting Mr. Temple.

"What do you mean?" asked Bob.

"Weren't there a bunch of German spies in Mexico, stirring things up there against us, during the war? Well, I'll bet there are some of the same breed there now making all this trouble for Mr. Hampton," said Frank.

"A good idea," said Mr. Temple, approvingly. "Well, boys, there will be no church for us today. This matter has got to be attended to."

CHAPTER VII

KIDNAPPED

"Not a trace, Bob. I don't know what to make of this."

"Nor I, Frank. A fellow wouldn't believe that right here near New York, in the most densely populated part of the East, two men could steal an airplane and escape without a trace."

"Oh, I don't know, Bob. You remember last winter when that aviator from the upper end of Long Island was last seen flying across the Sound toward the Connecticut sh.o.r.e and was never seen or heard of again."

"But, Frank, here forty-eight hours have pa.s.sed. Here we are, Tuesday morning. Dad has wired every city, town and hamlet in the East. Not a sign of the machine, nor of the men."

It was, in truth, Tuesday morning. The morning when, everything going as planned, they should have been setting out on their flight to the Hampton camp in New Mexico. Instead, the boys were moodily pecking at breakfast, the airplane had disappeared, and the trip seemed more and more remote.

To add to their worries, they had been unable to reopen communication with their chum, Jack Hampton, by radiophone, since that first and only time the previous Sat.u.r.day afternoon. All their efforts to call him met with no response. The day before, moreover, a telegram had been sent Mr. Hampton by Bob Temple's father, informing him in code of recent mysterious occurrences, including the theft of the airplane, telling him the boys had tried to call Jack by radiophone, but without response from his powerful New Mexico station, and asking whether all was well with him. No answer had yet been received.

"Mister Robert," said Mary, the maid, entering the breakfast room, as the two boys sat in moody silence, "your father wants you and Mister Frank in the library."

The boys hurried to the library at once, where they found Mr. Temple, very grave of face, bent above a lengthy telegram which he had just finished decoding.

"It's from Jack," he said, "And the poor fellow is in a lot of trouble. Listen."

He read:

"Dear Friends, Father has been kidnapped. Two men in airplane carried him away into Old Mexico. Since getting your telegram few minutes ago realize it may have been your airplane. Wasn't there and didn't see it but description of machine given by cowboy on the range who saw it all tallies with description of your machine."

Mr. Temple paused for breath, and Frank, who had been computing mentally, interrupted.

"Our plane could do it all right," he said. "That is, if--When did this happen?"

"Monday noon or a little later," said Mr. Temple.

"Well, they stole it sometime Sat.u.r.day night," said Frank. "Yes, they wouldn't have had to make more than eighty miles an hour steady flying to do it. But where did they get the petrol?"

"Why," Bob reminded him, "we had her stocked with oil and gas. And the spare tanks filled, too. That wasn't impossible."

Mr. Temple resumed:

"Haven't answered your radiophone calls because didn't get them. Have been so busy running around in circles, haven't had time to watch the telephone. But if you call me when you get this shall be on the watch.

Father was kidnapped Monday noon. No word from him. Need your help."

"He certainly does," said Mr. Temple, emphatically, as he concluded reading. "And he'll get it, too. Come on, boys, let's call him up."

Evidently Jack was on the watch for their signal, for he answered at once, and as soon as each had tuned to their private 1,800-metre wave length, the Temples and Frank were given the full details as to the kidnapping of Mr. Hampton.

He had been riding horseback across the range, miles from any oil derricks or pumping stations, on his way to visit one of the "independent" oil operators.

A lonesome cowboy hunting a stray was the only other human being in sight, and he was a half mile away. Suddenly out of the sky swooped an all-metal airplane, glistening in the sun. It made a beautiful landing on the sandy soil, b.u.mped along over a few clumps of mesquite, and came to rest close beside Mr. Hampton. The latter jumped from his horse, and started running toward it. Evidently, Jack thought, his father believed the Temples and Frank had unexpectedly arrived.

Then the watching cowboy saw two men leap from the airplane and start for Mr. Hampton, who turned as if to run. Thereupon, one of the two pointed a revolver at him and he turned, perforce, and surrendered. He was put into the airplane, the two men again climbed aboard, and the machine soared up into the sky before the astonished cowboy could more than set his horse in motion.

All this Jack explained and then asked:

"Mr. Temple, what would you advise me to do?"

"Does anybody else know of this?"

"Only the cowboy who saw it and I," said Jack. "This cowboy knew father by sight, and came direct to me with the information. I've made him promise not to tell anybody until he hears from me."

"That's right, Jack," said Mr. Temple, very earnestly. "This information must not get out. I believe, Jack, your father will be safe from harm and that the men who seized him are intent on embroiling Mexico and the United States. Now we don't want any more wars, Jack, and we must try to get your father back without the aid of troops."