"Chief, you're right!" he exclaimed, leaning forward. "You're right!

That spot of black was just where the old man was. .h.i.t. Now, what d'ye make of that?"

Drew drummed his fingers on the edge of the polished desk. He tapped his toes on the floor. He coughed and picked up the mirror for a second and longer glance at his face and neck. He tossed the mirror to the desk and swiveled slowly.

"What do I think of it?" he repeated, with flashing eyes. "I think there are features to this case I don't like!"

"Could it have been an accident, Chief? You might of got a bit of soot from the gun and then scratched your neck. Maybe that Harry Nichols put one over on us. The gun might have been fired, reloaded, and we never noticed it. Looks bad for Nichols and the girl."

Drew closed his eyelids tightly. His brow furrowed in deep thought.

"No," he said finally. "I don't think the soot or powder came from the pearl-handled revolver. I don't think so! It would seem to me, Delaney, that intuition is stronger than evidence. That girl and that boy rang true. That valet is above suspicion. The servants are to be trusted.

Stockbridge trusted them and he was noted for his shrewdness in picking men. The only mistake he ever made was Morphy. That individual was out to do the old man. He was a biter, bitten! I think we'll eliminate, for the time, Loris, Harry, the servants and German influences in the matter at hand. What was your idea?" Drew rubbed his neck beneath his ear, as he turned to his papers.

"I've forgotten it, Chief. That spot drove it all out. No, wait--say!

I've been thinking--this morning laying there and listening to the kids getting ready for school--that the powder we smelled in the library wasn't ordinary powder. I know a firecracker, or a regular Chinese smell when I get near one. That wasn't the kind I got. It was like something else. It was powder--all right--but----"

Drew lifted a sheet of paper. "I covered that," he said. "a.n.a.lysis made by Higgens, this morning, shows traces of smokeless-powder in Stockbridge's hair and about the bullet hole. There's a difference.

Now, I'm going further than that. I'm going to have those sc.r.a.pings I got from my neck looked at. If they are the same as the powder that was used to slay Stockbridge, we are getting on."

"There's lots of smokeless, Chief."

"That's the trouble--that's what we are right up against. Let's leave the footprints and the powder for a few minutes. Both are important.

They'll wait. See here!"

Drew raised a sheath of papers from his desk, turned with the chair, and started thumbing over the data he had acc.u.mulated.

"See here," he repeated absently. "First branch of the tree of Truth in this case is a stubborn one. It requires considerable work on our part to get to the end of it. I've sent out six operatives to scout the telephone calls and get me some light on them. I've kept some notes on what they have 'phoned in to me. The telephone company, the wire-chief at Gramercy Hill, and an official I know, have been enlisted in getting to the bottom of these calls. They have made progress. But, Delaney, of all the devilish inventions of man, a telephone is the most subtle.

It's a wonder to me we have found anything. It's the crook's one best tool. With it he can play safe, and we can't catch him!"

"What have you found, Chief?"

Drew held up a paper. "The first call, Delaney," he said, "was the one to the cemetery company's superintendent, notifying him to excavate a grave in the Stockbridges' family plot. Subtle suggestion, that, in the light of what followed."

"It was," said Delaney.

"This call has received all of the attention it deserved. It's the first of the series, and was perhaps made before the crook had time to cover himself completely. It has been traced to a slot booth in the Pennsylvania Railroad Station in the Woman's Waiting Room."

"Woman's?"

"Yes, Delaney. That is no criterion that a woman did the calling-up.

The girl there in charge of the pay-booths states that more men than women use the 'phones in that part of the station."

"Just our luck!"

"The toll collected on this call must have been thirty-five cents, including the war-tax. The superintendent says that the voice over the wire was thin and tired. He says he thought it was Dr. Conroy. He never gave the matter second consideration. Conroy, however, has a voice like a bull. We checked that up."

"Does the superintendent know Conroy?"

"No! Except by name!"

"Then, Chief, I don't see any use trying that lead. It begins and ends in air."

"It most certainly does! We'll cross it out. The next call for our investigation----"

"Which was?" asked Delaney, waking up.

"Which was the one notifying Stockbridge that he had about reached his span of life on this earth. I was there in that library when the call came in. Again, from the millionaire's description, this time, we have the thin, whispering voice on the wire. The man was probably the same.

He mentioned the cemetery letter which would establish that fact."

"I'm following you, Chief. Go on!"

Drew picked out a second sheet of paper from his pile. "We went after this call at the time, or soon after the time it was sent in," he said, tapping the sheet with his fingers. "I called the office here and had Harrigan get in touch with George Westlake, third vice-president of the telephone company. Westlake got busy."

Delaney eyed his unpolished shoes with a sage wink.

"Westlake turned things over," continued the detective. "He made a most thorough investigation. We have his word that there is no record of this call! The wire-chief at Gramercy Hill Exchange declares that it never went through the switchboard. That the connection had been made on the outside."

"From the air?"

"Looks that way. They tried everything and questioned everybody. No one talked with Stockbridge through the switchboard at Gramercy Hill, at or near that hour. Therefore, we must conclude, that, insomuch as I know somebody _did_ talk with him at that hour, the connection was made, either in the junction-box in the alley or behind the switchboard at Gramercy Hill Exchange."

"How about underground, Chief?"

"Impossible! That is--almost impossible. The cables are in conduit and sheathed with lead. It would be a poor place to tap in on a line. I'm going to presume that the man who tapped in knew his business. The junction-box in the alley is under suspicion. I think it was done there, in this manner." Drew paused and picked up a third sheet of hurriedly-written notes.

"A junction-box," he said, "is merely a small switchboard where the conduit ends and the house connections begin. It would have been easy for an expert to disconnect the two leads which led into Stockbridge's library, ring up with a low tension magneto, and then cut in with a testing set and a battery current and do the talking. That is what the trouble-man told us might have been done. He found no signs of tampering. He saw a tall man escaping down the alley. It would seem, Delaney, that this tall man is the one we're after. Perhaps, as you said, he left footprints. But footprints, like fingerprints, are not much use until you get the man who made them."

"What d'ye deduct in this second call--Chief?"

"That we've run squarely up against a blind wall. We'll drop it for a time and go to the third call."

"When was that?"

"Stockbridge was murdered at four minutes and eighteen seconds past twelve, by his own watch, Delaney. It was a very good watch! Now allowing for a movement of the hands on account of the fall, how are we to account for a telephone call sent into Gramercy Hill 9763--the library 'phone--at exactly five minutes past twelve from a slot-telephone booth at the east end of the Grand Central Railroad Station on Forty-second Street?"

"How did you get that, Chief?"

Drew chuckled and wheeled in his chair. "I got it," he said, "by simple arithmetic plus the vice-president's pull. Here's how it was found, Delaney. Easy as two and two. You remember the howler?"

"I'll never forget it, Chief! Not as long as I live!"

"The howler established considerable in this case. The chief operator remembers putting it on. She remembers the time. She looked back, after being jogged by George Westlake, and found that some one had called up Stockbridge a few minutes after twelve. It was probably this call to the old man that caused him to be near enough to the telephone to knock it over when he was shot. The operator did not hear the shot, but she remembers a thin, piping voice asking for Gramercy Hill 9763."

"The same guy, every time!" declared the operative, mopping his brow with his sleeve. "I'd like to have that fellow for five minutes, Chief!"

"We'll get him! We've got the time established twice. Stockbridge's watch fixes the murder at twelve-four-eighteen. The telephone call at five minutes past twelve, and the howler put on soon afterward, checks up. The old man was alive during the telephone call from the Grand Central, and dead when the howler was put on for the first time. Do you see that?"

Delaney frowned. "I see it and I don't," he said. "I'm all balled up, Chief. What with the magpie and the howler and a man shot in a locked room and the spot of soot on your neck--I'm all twisted into a knot. I think I'll go out and get a drink!"