with the machine-like rapidity and precision of their highly-specialized craft. After a few minutes, the work completed, the surgeon turned to the two men who had been watching him so intently, with a smile upon his clean-shaven face.
"Merely a scalp wound, Mr. Crane," he stated. "He should recover consciousness in an hour or so." Then, breaking in upon Seaton's exclamation, "It looks much worse than it really is. The bullet glanced off the skull instead of penetrating it, stunning him by the force of the blow. There are no indications that the brain is affected in any way, and while the affected area of the scalp is large, it is a clean wound and should heal rapidly. He will probably be up and around in a couple of days, and by the time his hair grows again, he will not be able to find a scar."
As he took his leave, the police and coroner arrived. After making a thorough investigation, in which they learned what had been stolen and shrewdly deduced the manner in which the robbery had been accomplished, they departed, taking with them the bodies. They were authorized by Crane to offer a reward of one million dollars for information leading to the arrest and conviction of the murderer. After everyone except the nurses had gone, Crane showed them the rooms they were to occupy while caring for the wounded man. As the surgeon had foretold, Shiro soon recovered consciousness. After telling his story he dropped into a deep sleep, and Seaton and Crane, after another telephonic conference with Prescott, retired for the rest of the night.
CHAPTER VI
The Object-Compass at Work
Prescott, after a sleepless night, joined Seaton and Crane at breakfast.
"What do you make of it, Mr. Prescott?" asked Crane. "Seaton here thinks it was DuQuesne, possibly acting for some foreign power, after our flying-machine to use in war. I think it was some big industrial concern after our power-plant. What is your opinion?"
"I haven't any," replied the great detective after a moment. "Either guess may be true, although I am almost positive that Dr. DuQuesne had nothing to do with it, either way. It was no ordinary burglary, that is certain from Shiro's story. It was done by someone who had exact information of your movements and habits. He chose a time when you were away, probably not so much from fear of you as because it was only in your absence that he could succeed as he did in getting all the guards out at once where he could handle them. He was a man with one accomplice or who worked alone, and who was almost exactly Seaton's size and build. He was undoubtedly an expert, as he blew the safe and searched the whole house without leaving a finger-print or any other clue, however slight, that I can find—a thing I have never before seen done in all my experience."
"His size should help in locating him," declared Crane. "While there are undoubtedly thousands of men of Dick's six-feet-one and two-fifths, they are fairly well scattered, are they not?"
"Yes, they are, but his very size only makes it worse. I have gone over all the records I could, in the short time I have had, and can't find an expert of that class with anywhere near that description."
"How about the third guard, the one who escaped?" asked Seaton.
"He wasn't here. It was his afternoon off, you know, and he said that he wouldn't come back into this job on a bet—that he wasn't afraid of anything ordinary, but he didn't like the looks of things out here. That sounded fishy to me, and I fired him. He may have been the leak, of course, though I have always found him reliable before. If he did leak, he must have got a whale of a slice for it. He is under constant watch, and if we can ever get anything on him, I will nail him to the cross. But that doesn't help get this affair straightened out. I haven't given up, of course, there are lots of things not tried yet, but I must admit that temporarily, at least, I am up a stump."
"Well," remarked Seaton, "that million-dollar reward will bring him in, sure. No honor that ever existed among thieves, or even among free-lances of diplomacy, could stand that strain."
"I'm not so sure of that, Dick," said Crane. "If either one of our ideas is the right one, very few men would know enough about the affair to give pertinent information, and they probably would not live long enough to enjoy the reward very thoroughly. Even a million dollars fails in that case."
"I rather agree with Mr. Crane, Seaton. If it were an ordinary affair—and I am as sure it is not as the police are that it is—a reward of that size would get us our man within two days. As it is, I doubt very much that the reward will do us any good. I'm afraid that it will never be claimed."
"Wonder if the Secret Service could help us out? They'd be interested if it should turn out to be some foreign power."
"I took it up with the Chief himself, just after it happened last night. He doesn't think that it can be a foreign country. He has their agents pretty well spotted, and the only one that could fill the bill—you know a man with that description and with the cold nerve to do the job would be apt to be known—was in San Francisco, the time this job was pulled off."
"The more you talk, the more I am convinced that it was DuQuesne himself," declared Seaton, positively. "He is almost exactly my size and build, is the only man I know of who could do anything with the solution after he got it, and he has nerve enough to do anything."
"I would like to think it was DuQuesne," replied the detective, thoughtfully, "but I'm afraid we'll have to count him out of it entirely. He has been under the constant surveillance of my best men ever since you mentioned him. We have detectaphones in his rooms, wires on his telephone, and are watching him night and day. He never goes out except to work, never has any except unimportant telephone calls, and the instruments register only the occasional scratching of a match, the rustle of papers, and other noises of a man studying. He's innocent."
"That may be true," assented Seaton doubtfully, "but you want to remember that he knows more about electricity than the guy that invented it, and I'm not sure that he can't talk to a detectaphone and make it say anything he wants it to. Anyway, we can soon settle it. Yesterday I made a special trip down to the Bureau, with some notes as an excuse, to set this object-compass on him," taking one of the small instruments from his pocket as he spoke. "I watched him a while last night, then fixed an alarm to wake me if the needle moved much, but it pointed steady all night. See! It's moving now. That means that he is going to work early, as usual. Now I'm morally certain that he's mixed up in this thing somewhere, and I'm not convinced that he isn't slipping one over on your men some way—he's a clever devil. I wonder if you wouldn't take this compass and watch him yourself tonight, just on general principles? Or let me do it. I'd be glad to. I say 'tonight' because if he did get the stuff here he didn't deliver it anywhere last night. It's just a chance, of course, but he may do it tonight."
After the compass had been explained to the detective he gladly consented to the plan, declaring that he would willingly spend the time just to watch such an unheard-of instrument work. After another hour of fruitless discussion Prescott took his leave, saying that he would mount an impregnable guard from that time on.
Late that evening Prescott joined the two men who were watching DuQuesne's house. They reported that all was perfectly quiet, as usual. The scientist was in his library, the instruments registering only the usual occasional faint sounds of a man absorbed in study. But after an hour of waiting, and while the microphones made a noise as of rustling papers, the needle of the compass moved. It dipped slowly toward the earth as though DuQuesne were descending into the cellar, but at the same time the shadow of his unmistakable profile was thrown upon the window shade as he apparently crossed the room.
"Can't you hear him walk?" demanded Prescott.
"No. He has heavy Turkish rugs all over the library, and he always walks very lightly, besides."
Prescott watched the needle in amazement as it dipped deeper and deeper, pointing down into the earth almost under his feet and then behind him, as though DuQuesne had walked beneath him. He did not, could not, believe it. He was certain that something had gone wrong with the strange instrument in his hand, nevertheless he followed the pointing needle. It led him beside Park Road, down the hill, straight