Dropping "Who's Who" to the floor, Dundee flung open his living room door and raced down three flights of stairs. He brought up, panting, at the door of the bas.e.m.e.nt. It was not locked and in another minute he was standing before the big hot-air furnace. Above the fire box was a big metal compartment--the reservoir for the heated air. And set into the reservoir, to conduct the heat to the regions above, were three huge pipes.

With strength augmented by excitement, Dundee tugged and tore at one of the pipes until he had dislodged it. Then thrusting his hand into the heat reservoir, he groped until he had found what he had known must be there--_Judge Marshall's automatic, with the Maxim silencer screwed upon the end of its short nose_.

At last he held in his hands the weapon with which Nita Leigh Selim and Dexter Sprague had been murdered.

The ingeniousness of his own attempted murder moved him to such profound admiration that he could scarcely feel resentment. If, in the excitement of hunting for a promised clue, he had gone directly to the shelf, standing in front of the hole in the register into which the end of the silencer had been jammed, so that it showed scarcely at all, even to eyes looking for it, he would now have been dead. And the gun and silencer, after hurtling down the big hot-air pipe behind the register, could have lain hidden for months, even years, in the heat reservoir of the furnace.

With the weapon carefully wrapped in his handkerchief, Dundee went up the stairs almost as swiftly as he had gone down them, meeting no one on the way to his rooms on the top floor.

"My most heartfelt thanks to you, Cap'n!" he greeted his parrot. "If you had not squawked last night and so frightened the murderer that he made the vital error of covering your cage, I should never have annoyed you again with my Sherlock ruminations on cases which do not interest you in the slightest."

The parrot cackled hoa.r.s.ely, but Dundee paid him scant attention. He picked up the now harmless "Who's Who" and turned to page 410, a corner of which had disappeared with the string that was still fastened to the hair-trigger hammer of the Colt's .32. Very clever and very simple! The murderer of two people and the would-be murderer of a third had had only to unscrew the metal covering of the register, wedge the end of the silencer into one of the many holes, replace the screws, and paste the end of the string, drawn through another hole hidden by the tapestry, to a page of the book he had selected as the one most likely to appeal to a detective as a clue source....

No, wait! He had had to do more! Dundee bent and examined the metal cover of the register. The circ.u.mference of the hole the murderer had chosen as the one which would be directly in front of Dundee's heart gleamed brightly. It had been necessary to enlarge it considerably. _The murderer had left a trace after all!_

But the book was open in Dundee's hands and his eyes rapidly scanned page 410. And he found what the murderer had not expected him to live to read, but which he had counted on as an explanation of the note which the police would have puzzled over, if all had gone well with his scheme....

CHAPTER TWENTY-SEVEN

Dundee laughed, the parrot which had saved his life echoing his mirth raucously, as his eyes. .h.i.t upon the following lines of fine print halfway down the third column of page 410 of "Who's Who in America":

BURNS, William John, detective; b. Baltimore, Oct. 19, 1861--

"A taunt and a joke which turned sour, 'my dear Watson'!" he exulted to the parrot. "A joke I was not intended to live to laugh over!"

He closed the book and replaced it in the bookcase, careless of fingerprints, for he was sure the murderer had been too clever to leave any behind him in that room--or upon the gun and silencer either, for that matter.

Interestedly, Dundee surveyed the scene of his attempted murder. If he had unsuspectingly gone up to the high shelf to reach for the book he would have stood so close to the register that there would have been powder burns on his shirt front--just as there had been on Dexter Sprague's. And he would have been shot so near an open window--no chance for fingerprints there, either, since he had not closed the windows on his departure for New York, not wishing to return to a stuffy apartment--that the police would have been justified in thinking he had been shot from outside. It was an old-fashioned house in more ways than in the manner of its heating. Outside of one of his two unscreened windows there was an iron grating--the topmost landing of a fire escape.

Dundee could imagine Captain Strawn's positiveness in placing the murderer there--crouching in wait for his victim....

Yes, d.a.m.ned ingenious, this attempted murder! Undoubtedly Strawn would have dismissed the note as the work of a crank, not hitting upon the fact that it had been written in that very room, on Dundee's own typewriter and stationery. Strawn might even have got a mournful sort of amus.e.m.e.nt out of the fact that Dundee had been advised to call upon a greater detective than himself for a.s.sistance!... Yes, ingenious indeed!

And so amazingly simple----

Suddenly the young detective s.n.a.t.c.hed for his hat. If the murderer was so ingenious in this case, might he not have been equally clever in planning and executing the murder of Nita Leigh Selim?

Twenty minutes later he parked his car in the rutty road before the Selim house in Primrose Meadows, and honked his horn loudly to attract the attention of the plainclothesmen Captain Strawn had detailed immediately after the murder to guard the premises during the day. There was no answer. And a violent ringing of the doorbell also brought no response. The guard had been withdrawn, probably to join the small army of plainclothesmen and patrolmen who had been foolishly and futilely searching for the New York gunman--the keystone of Captain Strawn's exploded theory.

With an oath, Dundee used his skeleton key to release the Yale lock with which the front door was equipped. Straight down the main hall he went and into the little foyer between the hall and Nita's bedroom. He s.n.a.t.c.hed up the telephone and to his relief it was not dead. He gave the number of Captain Strawn's home, and had the pleasure of learning that he had interrupted his former chief at a late Sunday breakfast.

"When did you withdraw the guard from the Selim house?" he asked abruptly, cutting short Strawn's cordial welcome-home.

"Late Thursday afternoon," the Chief of the Homicide Squad answered belligerently. "I needed all my men, and the Selim house had been gone over with a fine tooth comb half a dozen times.... Why?"

"Oh, nothing!" Dundee retorted wearily, and hung up the receiver after a.s.suring his old friend that he would call on him later in the day.

No use to explain now to Strawn that the murderer had been given every chance to remove any betraying traces of his crime. Besides, his first excited hunch, after his own attempted murder, might very well be a wild, groundless one. In his--Dundee's case--the impossibility of the murder's being delayed or arranged so that the detective might be slain when the whole "crowd" was a.s.sembled was obvious. The murderer had read in a late Sat.u.r.day afternoon extra--a copy of which was now in Dundee's pocket--District Attorney Sanderson's boast to the press that his office had been working on an entirely different theory than that which connected the two murders with "Swallow-tail Sammy," that Special Investigator Dundee, _expected back in Hamilton early Sunday morning_, had been investigating Nita Leigh's past life in New York. And despite Dundee's telegraphed warning, he had hinted sensational revelations connected with the twelve-year-old royal blue velvet dress which Nita had chosen to be her shroud. And in his desire to rea.s.sure the public through the press, Sanderson had mysteriously promised even more specific revelations than Dundee had actually brought home with him.

Prodded by reporters, Sanderson had admitted that he did not himself know the nature of those revelations.

The exasperated young detective could picture the murderer reading those sensational hints and promises, could imagine his panic, the need for immediate action, so that Special Investigator Dundee should not live to tell the tale of his New York discoveries to the district attorney or anyone else.

But whether he was right or wrong, Dundee determined to give his hunch a chance. He went into the over-ornate bedroom in which Nita Leigh Selim had been murdered--shot through the back as she sat at her dressing-table powdering her face. If her murder had been accomplished by mechanical means, how had it been done? There was no hot-air register here....

From the dressing-table Dundee walked to the window, upon whose pale-green frame there was still the tiny pencil mark which Dr. Price had drawn, to indicate the end of the path along which the bullet had traveled, provided it had traveled so far. Nothing _here_ to aid in a mechanical murder--

But in a flash Dundee changed his mind. For just slightly above the pencil mark there was a small dent in the soft painted pine of the window frame.

And before his mind could frame words and sentences he thought he saw how Nita Leigh had been murdered.

Nothing here?... _Not now, because he himself had taken the lamp to the courthouse for safe-keeping._

He saw it clearly in imagination--that bronze floor-lamp which Lydia Carr had given to Nita Leigh, its big round bowl studded with great jewels of colored gla.s.s. And in recalling every detail of the lamp he saw what he had dismissed as of no importance at the time, in the excitement of finding that the lamp's bulb had been shattered by the "bang or b.u.mp" which Flora Miles had described. _One of the big gla.s.s jewels had been missing, leaving an unsightly hole._

No wonder there had been a "bang or b.u.mp" hard enough to dent the frame of the window! For if his hunch was correct, the gun, wedged into the big bowl, with the silencer slightly protruding from the jewel-hole, had "kicked," just as it had kicked an hour before, when it had dislodged itself from the hole in the hot-air register and clattered down the big pipe to the heat reservoir of the furnace.

That the big lamp, when he, following Strawn, had first examined the scene of Nita's murder, had not stood in front of the window frame, did not dampen Dundee's excitement in the least. After Karen Marshall's scream that room had been filled with excited people, who had rushed about, looking out of the window for the murderer and doing all the other things which terror-stricken people do in such a crisis. No, the murderer--or murderess--had found no difficulty in shifting the big lamp one foot nearer the chaise longue, to the place it had always occupied before.

But--_how_ had the gun been fired from the lamp? Electrically? Another picture flashed into Dundee's mind. He saw himself stooping, on Monday afternoon, to see if the plug of the lamp's cord had been pulled from the socket, saw it again as it was then--nearly out, so that no current could pa.s.s from the baseboard outlet under the bookcase into the bronze lamp. How far from the truth his conclusion that Monday had been!

But what was the _real_ truth?

Suddenly Dundee flung back the moss-green Wilton rug which almost entirely covered the bedroom floor and revealed the bell which Dexter Sprague had rigged up so that Nita might summon Lydia from her bas.e.m.e.nt room, in case of dire need--a precaution with which the murderer was probably familiar, since Lois Dunlap might innocently have spread the news of its existence.

There was a half-inch hole in the hardwood floor, and out of it issued a length of green electric cord, connected with two small, flat metal plates, one upon the other, so that when stepped upon a bell would ring in Lydia's bas.e.m.e.nt room.

But there was something odd about the wire. Although it was obviously new, a section of it near the two metal plates was wrapped with black adhesive tape. Another memory knocked for attention upon Dundee's mind.

_The long cord of the bronze lamp had been mended with exactly the same sort of tape--about a foot from where it ended in the contact plug._

Within another two minutes, Dundee, with a flashlight he had found in the kitchen, was exploring the dark, earthy portion of the bas.e.m.e.nt which lay directly to the east of Lydia Carr's bas.e.m.e.nt room. And he found what he was looking for--adhesive tape wrapped about the wire which had been dropped through the floor of Nita's room before it had been carried, by means of another hole, into Lydia's room.

He was too late--thanks to Captain Strawn. The bell which Sprague had rigged up was in working order again. But as he was pa.s.sing out of the bas.e.m.e.nt he glanced at the ceiling of the large room devoted to furnace, hot-water heater and laundry tubs. And in the ceiling he saw a hole....

The murderer had left a trace he could not obliterate!

At three o'clock that Sunday afternoon Bonnie Dundee, fatigued after a strenuous day, and suffering, to his own somewhat disgusted amus.e.m.e.nt, from reaction--even a detective feels some shock at having narrowly escaped death--permitted himself the luxury of a call upon Penny Crain.

He found the girl and her mother playing anagrams. After greeting him, Mrs. Crain rose, to surrender her place to the visitor.

"_You_ play with this girl of mine, Mr. Dundee. She's too clever for me!

She's beaten me every game so far, and when I plead for two-handed bridge as a chance to get even, she shudders at the very word."

"Why did you drag poor Ralph away from his dinner here today?" Penny demanded, scrambling the little wooden blocks until they made a weird pattern of letters.

"Because I wanted to find out exactly _how_ Nita Selim was killed--and I did," Dundee answered. "I wish I knew as well _who_ murdered her!"