THE passing of the hours had served only to complicate the Hamilton case. At the outset it had been pregnant with the unusual, but not fraught with any very great mystery. Now, however, the aspect had altered.

In the beginning David Carroll had before him the fact of the murder and three persons who confessed to the crime. In addition to that he had a notorious criminal whose coincidental presence at the scene of the shooting had fastened about him a web of circumstantial evidence sufficient to convict before the most open-minded jury.

But now it had changed. Proof, of an almost incontrovertible nature, had been furnished that neither Eunice Duval nor her fiancé had killed Hamilton; the bullet from the revolver which Eunice had used had been located at a point where it could not have gone had either Badger or Hartigan fired it. It was fairly well settled that Vincent Harrelson had not fired. And Badger’s shot had been accounted for as the one which had wounded Hartigan.

There was the matter of the six seconds of darkness, already explained by Hartigan’s perfectly plausible confession that he had extinguished the lights to facilitate his escape and turned them on again after being shot so as to avoid detection in his sanctuary behind the screen. It had also been pretty well proven that three shots were fired; Badger’s and Eunice’s in the first few seconds of darkness, neither shot of which struck Hamilton, and the fatal shot, which was fired immediately after the lights went on.

By a simple process of deduction, that shot must have been fired by Hartigan; yet, if it were true that Badger’s bullet had found its mark in Hartigan’s arm, the burglar’s contention that he had not fired at all must be believed. His wrist was shattered by the bullet, and firing a revolver with that hand would have been out of the question, and investigation had fairly well proven that Hartigan was not capable of shooting with his left hand.

On the face of the evidence it seemed patent that Hartigan must be the guilty man, yet Carroll entertained grave doubts. He wanted to know more about the yegg whom Donaldson had addressed so familiarly as “Lefty” and there was still the butler to be accounted for. Besides, the maid had insisted stubbornly that in spite of her hysteria she had noticed that the sound of the final shot was clearer and more distinct than its predecessors—she immediately had asserted that it must have come from the garden.

They had left the maid upstairs in the care of Mrs. Faber, and of Maggie, the cook. They assembled in the living room, Carroll and two of his men—the third having Hartigan in a chair on the veranda; Eunice and Vincent Harrelson; Police Commissioner Hall and Denson, the lawyer. And last, but undeniably not least, was Barrett Rollins, chief of the city’s plain-clothes detective force.

Rollins was seated near the door through which Hamilton and young Vincent had struggled just before the former was killed. His straight-legged chair was tilted back against the wall, his broganed feet battered viciously against the slender legs, a rank pipe was clenched firmly between his none-too-even teeth—unlighted. His clothes, although very quiet and immaculately pressed, gave a subtle impression of untidiness—it may have been the narrow collar or the crooked set of his tie; but, whatever it was, the professional detective seemed out of place in the picture.

Furthermore, he was nervous and fidgety, and that despite the fact that he was making a visible effort to keep himself under control. Hall, glancing at him not unkindly—for he admired the man’s indomitable will and unflinching courage even while he detested him personally—imagined that he was still chafing at the bit, disgusted with Carroll’s elevation to a position above him on the present case.

And, yet, Hall was glad now that he had summoned Carroll’s aid. If he had done nothing else, Carroll had at least proved that the three original confessors—two of whom really believed their guilt —had not killed Hamilton. He had not done it with any display of mental pyrotechnics, with any pussy-footing around with an eye glued to a magnifying glass; yet he had done it. His methods had been simple to the point of being ludicrous—as he himself had explained, he had simply set out to marshal all facts and separate the relevant from the irrelevant, then to weigh the pros and cons of the former in the balance.

Rollins, Hall fancied, would have done nothing of the kind. From the moment Rollins had appeared at headquarters close on to midnight of the previous day, he had stubbornly—almost too stubbornly—maintained that Red Hartigan was the murderer.

There was sound reasoning behind his contention; no doubt about that, for in the first place Rollins knew nothing about Frederick Badger. Hall wondered idly why Carroll had kept all knowledge of Badger from Rollins. He knew that Carroll did nothing without a motive, but what particular object that move could have in view he was unable to understand. That it had one he did not doubt; but what?

A half dozen times since then the natural antagonism between the polished, placid Carroll and the brusque, almost brutal Rollins had flared to the point of physical clash. The men seemed to be going to opposite extremes in the matter; Rollins eager to drop the case, Carroll just as determined to stick to it until every little detail was known to him. Carroll’s was the best method theoretically; Rollins’ was more conducive to speed. And now that the only remaining suspect was a professional burglar, Hall felt quite willing that the man should take his chances before a jury of twelve of his peers.

At that, Hall could not understand the part the butler had played in the tragedy. The man had been a new one in Hamilton’s employ, true; but Hall knew the dead man well enough to realize that he would have employed no male domestic on the strength of anything but the very best of references. It was inconceivable that the man was what circumstances indicated.

The facts of the burglary were plain enough; the butler helping Hartigan and the man called Lefty on the inside of the house, while a fourth kept watch outside. Not by any means an original plan of procedure, yet one which, in view of what had transpired, complicated things considerably.

There was, for instance, the matter of Hartigan’s revolver, from which one bullet had been fired. Hartigan had stubbornly maintained that he had no revolver, although his contention in itself was subject to a hundred-per-cent discount in view of the fact that such a statement, if believed, would automatically absolve him. But there was the gun—and in contravention of the damning fact and in support of Hartigan’s statement there was the casual story of the maid recounting the conversation between the butler and Lefty regarding Hartigan’s revolver; the latter’s contention that Hartigan did carry a gun and the former’s that he had searched him and was positive that he did not.

Summed up, three of the original principals in the case had been cleared absolutely; the fourth had developed mitigating evidence. And the question of who actually killed Hamilton was apparently farther from solution than it had been a half hour after the crime was committed.

It was at this juncture, when matters had apparently reached an impasse, that the telephone on the centre table jangled impatiently. Carroll rose to answer it. The forelegs of Rollins’ chair came down slowly to the floor.

“Hello, hello! Yes, this is Mr. Carroll. Oh, that you, Donaldson?”

“Yes, indeed.”

Rollins’ eyes popped open. Hall and Denson rose abruptly and stood rigidly by their chairs. Donaldson! Donaldson, the butler! Asking for and speaking to Carroll! And Carroll apparently not at all surprised. Carroll’s voice went on smoothly:

“Good!… That’s fine… Yes, at Hamilton’s house. … Come on down, won’t you? … Yes. … Good-bye?”

He placed the receiver gently on the hook and turned smilingly to face the others; the group whose blank faces and eyes gave evidence to the surprise they felt. A dull flush had mounted to Rollins’ forehead—it was as though he had been tricked, and he was angry. It was Rollins who spoke:

“Who was that on the phone then, Mr. Carroll?”

“Just Donaldson,” came the quiet answer. “I had been waiting for that call.”

Rollins leaned forward tensely.

“You had been waitin’ for Donaldson to call you?

“Why, yes! What’s wrong about that?”

Rollins produced a large handkerchief, lavender-bordered, and mopped his forehead.

“What th’ hell does it all mean?” he asked peculiarly. “I don’t seem to git it.”

“Nor I,” chimed in Denson.

“Nor do I, Mr. Carroll,” said Hall. “What is it?”

“Very simple,” came the placid answer. “Donaldson is one of the best detectives on my personal staff!

A sudden blank silence fell upon them. Rollins rose abruptly and walked to the window.

“You didn’t tell us,” accused Denson. Hall nodded.

“No-o,” said Carroll slowly; “there wasn’t any use. You see, I knew who Donaldson was, and I wasn’t at all worried over his complicity in the affair. So now that we’re all satisfied there’s——

Rollins whirled and confronted Carroll with a return of his old belligerence.

“We’re not!” he snapped furiously. “Not by a dam’ sight! S’pose you are in charge of this case—does that give you any right to make a fool outa me? Huh! Does it?”

Carroll controlled himself beautifully; almost too well.

“Here, here! What’s all the excitement, Rollins?”

“Excitement enough. Whatcha think I am, a schoolboy? A correspondence-school detective? Huh? I ask you that? Well, if you want to know what I think of it—I think you an’ your whole messy crowd can go plumb to the devil! Get that?”

“Wait a minute, Rollins; wa-a-a-it a minute! You’re flying off the handle too quick.”

“It’s none of your business. You’ve had me trotting around with you like a monkey on the end of a string. You ain’t told me a thing more than you’ve told any one else. You got me to sit up here an’ make a fool of myself when all the time you knew Donaldson was in on the know of it. I’m finished! Done! That goes as she lays, Mr. Hall. You can take my resignation an’ make this tea-hound, five-o’clock-in-the-afternoon detective head of your plain-clothes force. Bull! A swell cop you’d make, Carroll! Why, by God——

But Carroll refused to lose his temper. Instead, his voice took on an almost pleading note, and he laid his hand lightly on Rollins’ arm.

“Come, come now, old man!” he said in a wheedling tone. “That’s no way to lose your head. What if I did keep you in the dark about being wise to Donaldson? Can’t you see that I was only doing it to save my own face in case he flivvered? Just suppose I went spouting around that Donaldson was on my staff, and suppose he had double-crossed me and really made a getaway; I’d have been a sweet laughing-stock then, Rollins. Can’t you see that? Sure you can—you know you’d play the game the same way. I’ll bet you know something about this very case that I don’t know; hey?”

Rollins subsided suddenly, apparently mollified.

“Whatdaya mean,” he growled surlily, “I know somethin’ about this case?”

“Haven’t you run across some little clue or something that you’ve kept to yourself; just some little tiny thing that you’re trying to run down on your own so as to show me up?”

Rollins was plainly at a loss for an interpretation of Carroll’s meaning.

“Come now,” pursued the smaller man, “isn’t that a fact?”

Rollins’ big hands went to his hips, and he stared into Carroll’s eyes aggressively.

“What in th’ hell you drivin’ at?” he questioned furiously. “Tryin’ to make a monkey out of me again? ’Cause if you are——

“No, indeed; believe me, Rollins, nothing is farther from my mind. If I’ve done you an injustice, I’m sorry. Only, please, for the sake of the audience, let us not have any more of this eternal bickering and recrimination. It don’t get either of us anywhere, and one of these times you’ll go too far.”

“I don’t give a——

“Whoa! Careful, Rollins; no use straining good nature to the breaking point. Now let’s be sensible.”

Rollins subsided as suddenly as he had flared up. He seated himself again and tilted his chair back against the wall with assumed nonchalance.

“If that’s the case,” he said, “s’pose you tell us how Donaldson happens to be your detective.”

“No-o, I’m afraid I can’t do that.”

“You mean you won’t!”

“Please don’t translate my meanings to fit your beliefs. I said that I can’t and I mean can’t! My original business, the thing which resulted in Donaldson’s employment in this household as butler, had nothing whatever to do with this murder case. And I don’t care to discuss the business of the man who has paid me a retainer. That’s all.” The suspicion of a twinkle flashed in Carroll’s eyes as he added briefly: “That must appeal to your sense of ethics.”

Rollins shook his head.

“Sounds like foolishness to me,” he said. “An’ if you’re goin’ to keep things to yourself I don’t see what you want me hangin’ around for.” He started to rise, but Carroll motioned him back.

“No, I’d rather have you stay. Just as I’ve told those gentlemen—there’s always more than an even chance that my mind will get on the wrong track and that I’ll make a mistake somewhere—and just as two heads are better than one, four are better than three.”

“Especially,” snapped Rollins, “where one of ’em’s solid ivory.”

Carroll grinned amiably.

“Yes, especially where one is of solid ivory.”

The front-door bell rang twice—then once. Carroll strode toward the hall door.

“Donaldson,” he flung back; “I’m sure that’s who it is.”

He disappeared into the hall, and within three minutes was back, followed by Donaldson, unkempt, his face showing the lack of sleep the previous night, his clothes streaked with dirt. Nor was Donaldson alone. On the ex-butler’s right wrist was one of a pair of handcuffs. The other handcuff was tightly clamped on the wrist of the slender, furtive-eyed man with him. The two handcuffs were connected by a competent-looking chain.

As for the stranger, he, too, was dishevelled; it was quite evident that his capture had not been unresisted. He glanced apprehensively about the room, and finally his eyes rested on Barrett Rollins. He sighed and chewed nervously at his under lip.

“Who is that with you, Donaldson?” questioned Carroll innocently.

The butler smiled slightly and waved his free hand toward the captive.

“Mister Lefty Scammon, alias Shifty, alias a half dozen other things.”

“And why did you make him prisoner?”

Donaldson smiled the smile of supreme triumph. It was his big moment.

“Lefty Scammon,” he said oracularly, “is the man who murdered Mr. Hamilton!