"Accident is out of the question, John Davidson." The hands of the clock were moving toward midnight in Klein's restaurant, but mugs were still clinking, dishes rattling and waiters hurriedly cleansing soiled tables with their towels. The freedom of the saloon had been extended to the victorious fire-fighters, who, after supping with Duke Humphrey, were not at all reluctant to lunch with Commoner Klein.

"A health to Carl Klein," shouted one, tossing a tumblerful high in air.

"Your health!" the place echoed, as the whole group stood up and shouted a rousing toast. They were tough, middle-sized fellows, all of them, of the true fireman's build, which is just a shade taller and broader than a sailor's. The smiling old German hovered near and bowed and rubbed his hands in appreciation. To judge from the girth under his apron, he was himself a worshiper of the worthy trinity, breakfast, dinner and supper, which he served. The two men chattering in low tones at a side table had not stood up or noticed the interruption.

"I can't believe it, McCausland," answered John Davidson, the fire marshal. "There is no motive. It's devilish. It's beneath flesh and blood. Four lives already and heaven knows how many more. It isn't in human kind to do that without a reason."

"Mankind is my kind, too," answered McCausland, pleasantly, but in such a manner as to convey the idea that he was a diver of some experience into the deep-sea depths of human turpitude. "But suppose we look at the status quo. Everybody—Wotherspoon, Chandler and all the others—agreed that the fire must have been going some time when the servant-girl ran out of the house. If her story is to be believed, and she never turned a hair under cross-questioning, you'll allow?"

"The girl's fair spoken, I admit that," answered the marshal.

"Then the blaze started in a room two flights above the only fire which was going in the house, and that one a low coal fire in the cook stove. The cook stove and the study-hearth get their drafts from different chimneys. No possible connection there?"

"No," answered the marshal, for McCausland's last inflection had been slightly interrogative.

"The cast-away cigar doesn't fit," continued his companion, telling off the thumb on his chubby left hand. "There was no tobacco allowed in the house. Mungovan, their last coachman, was discharged for smoking on the sly. The professor was eccentric, you know, and this was the stanchest of his dogmas."

"Well?"

"No boys with firecrackers playing around. It's the lull between the 17th of June and the Fourth."

"No."

"No phosphorescent rat-bane on the premises," went on McCausland, telling off finger after finger. "You heard what the domestic said?"

"Yes; she was positive about that."

"Because they were not troubled with mice. Another accidental cause removed. But if rodents were swarming like flies in a meat shop, I don't see what substance more combustible than the pasted bindings of old books they could have found in that library to nibble. The lucifers were all kept in a safe downstairs, excepting a few for the sleeping-rooms."

"That's true, but——"

"Number six," interrupted McCausland. "What shall it be? Cotton waste taking fire spontaneously? Benzine? Naphtha varnish? Celluloid? None of them about, according to Bertha. I'm at my rope's end. Where are you?"

"Do you suppose they have been as careful since the professor died?" asked the marshal.

"That was only four days ago and the study has been locked ever since. Only opened fifteen minutes before the fire."

"Aren't you done guzzling yet?" broke in a strident tone of command from the open door. Chief Federhen's face was haggard and sooty, and his voice, naturally harsh, had a ragged edge from shouting that grated on the ear like the squawking of a peacock. But the firemen leaped immediately to attention. They did not resent their gray chief's reprimand, for they knew that he himself had gone without any supper at all and that he stood ready at that moment to lead wherever he ordered them to follow. In personal courage, as well as generalship, he was believed to be the foremost chief in the country, and, though not exactly popular personally, he was professionally adored. Only the insurance companies had ever ventured to criticise his bold methods, and they, as everybody knows, are simple-minded idealists, who expect an immunity from fire such as even the arctic regions can hardly enjoy.

"Take your machine alongside of fourteen, Tyrrell, and keep two lines on the Harmon building all night."

"All right, chief," answered Capt. Tyrrell, and his men followed him out through the curious crowd that stood peeking in on their collation.

"Impossible!" exclaimed the marshal, raising his voice, now that they were nearly alone.

"Impossible, that's what I say," smiled McCausland; "we're not living in fairyland. This is earth, where effects have causes."

"But who would have the heart to set it?"

McCausland shrugged his shoulders.

"If that's your impossible," he replied, "in the case of my own son, I'd rather his defense were a concrete alibi."

Inspector McCausland was a detective of the good old school, renowned in many states and not unknown to Scotland Yard and the keen Parisians. Nature had favored him with an exterior of deceptive smoothness. No vulpine contraction of the muzzle, such as would have suggested the sleuth and invited suspicion. Round, florid, pleasant-faced, a little sloping in the shoulders, decidedly suave of voice and genial in manner, he did not look the figure to be feared. Yet some, not easily frightened, would depart in haste from the neighborhood of Richard McCausland.

"The only living occupants of the room," he continued, unfolding his chain of reasoning to the still skeptical marshal, "at the time when Bertha went in, were the St. Bernard, Sire, whose barking had attracted her attention upstairs, and the canary bird, whose life she tried to save."

"Probably the delicate creature was dead when she opened the door," said the marshal.

"At any rate, it is impossible that an old dog, sleeping on the mat, or a golden-feathered songster, whistling in his cage, could be the author of this fire——"

"And loss of life."

"If the housemaid is telling the truth there was some other cause; and if she is lying," he concluded, arising to go, "it must be to cover up carelessness or guilt, either on her own part or on the part of some one in whom she takes an interest."

Intimate associates found McCausland a rollicking companion; but, in the pursuit of crime, he was a practical believer in the doctrine of total depravity, or, rather, to be just, he knew the potential evil which is harbored in every human heart until some life-or-death temptation effects, perhaps, the wreck of honor and humanity.

"Well, this is another feather in Federhen's cap," said the marshal, cheerily, at the door.

"He must share it with Jupiter Pluvius," answered McCausland.

As dark came on there had been a heavy fall of rain, which dampened the roofs and stifled many a darting tongue and incipient blaze in the vicinity, though it appeared to have no more effect on the body of the fire than so much fuel thrown into its maw. But it had enabled Federhen to concentrate his streams, which before this had necessarily been scattered about, protecting exposed points of danger. In fact, one or two serious subsidiary fires had only been checked with the utmost difficulty. If either of them had extended, and the Bay quarter once fairly caught, 500 poor families might have been ruined and two hotels and one depot would have been included in the loss.

At 6:45 Federhen had issued an order to blow up the Columbia shoe store building. Against the frantic protest of the owners his oracular answer was "Necessity!" and a high-handed jostle of the remonstrants to one side. The magazines were promptly laid and a wide space cleared. Precision and dispatch followed, like two leashed hounds, in the footsteps of the chief. At 7 o'clock, with a mammoth concussion, the middle of the building seemed lifted bodily into midair. Its walls caved in, and at once twenty lines of hose were wetting down the debris, while pickax men began widening still further the breach on the side toward the van of the approaching fire. This corner building laid low, the flames were sixty yards away from the depot, and all their surging and leaping failed to clear the gap. Confined at last, assaulted from every side, drenched, smothered and confounded, they spent their rage in a blind, internal fuming.

Those who returned to visit the fire in the evening, attracted, perhaps, by the noise of the last concussion, witnessed a miraculous transformation. The black night made a spacious and harmonious background for the flames, now a spectacle of sinister beauty, charging heavenward solidly to great heights only to flutter back and writhe at their manifest impotence. The streets below, flushed with rain, were glistening in the lamplight and the awestruck wonder of the crowd had subsided to a mere vulgar curiosity about details. Already the event was old to many, its solemn lesson and the revelation of underlying forces making only a shallow impress on shallow minds. Gangs of rowdies swung to and fro, elbowing respectable sight-seers into the puddles and rendering night hideous with their ill-timed pranks and depredations, like prowlers stripping the slain after battle.

The police were occupied guarding the ropes and ejecting without ceremony all intruders whose credentials were imperfect. Lines of hose lay about in inextricable confusion, half-buried in an amalgam of lake water, litter and mud, while at every corner the engines still sent up showers of sparks, the rhythm of their dull pumping resounding through the city like the labored beatings of some giant heart. Comments on the losses, the injuries, the probable hour when the flames would be conquered, beguiled the ranks of spectators who lined the ropes, those behind crushing forward as the front file yielded place, and drinking in all they could (not much at that distance), until the exhaustion of their interest in turn became evident by their repeated yawns. It was Saturday night, the late night in America, but by 11 o'clock there were gaps in the solid phalanxes and the homeward-bound stream far outnumbered that flowing toward the still vigorous but dull-red and smoke-colored sheet of fire.

Eleven was just ringing when a young man rushed up to the lines stretched across Cazenove street at its junction with Meridian, and half by force, half by entreaty, breasted his way to the rope.

"I wish to pass, officer; my property is among those burned," he said.

"Your property?" echoed the policeman, a phlegmatic-looking fellow. The youth was not over 21 and Higgins had heard this story at least a dozen times within an hour. His orders were to throw the burden of proof in every case upon the petitioner.

"Yes; that is to say, not mine, but my uncle's. I am a nephew of Prof. Arnold and lived with him."

The slight correction which the young man made in his explanation evidently prejudiced his cause in the policeman's eyes—as if confusion were a mark peculiar to the glib kinsmen of Ananias. The youth had slipped under the rope and the crowd craned near, expecting an altercation.

"Get back there!" came the sharp rebuke, and a heavy hand was laid on the young man's breast, gathering up the lapels of his coat and half his vest bosom.

"But my uncle's house is burned, I tell you," he protested.

"Outside!"

"I am also a member of the press."

"Outside the ropes!"

"You're a bully," cried the young citizen, pushing sturdily on his own side and fairly holding his own. "Sergeant!"

The sergeant in charge had come over when he saw trouble brewing and stepped closer at this personal appeal.

"I think you must know me. My name is Floyd. I am a nephew of Prof. Arnold, in whose house the fire is said to have started. Am I refused permission to pass the ropes?"

"I'm afraid there's little to be seen of your uncle's house, Mr. Floyd," quietly answered the sergeant, who knew him. "This gentleman is all right, Higgins."

Higgins nonchalantly moved a few steps off, doubtless reflecting that he had only erred on the side of vigilance.

"But the servants—do you know where they may be found?"

"Try opposite. They're still at home. The wind was the other way, you see."

The young man sped up to the site of his former home. One look at the black ruin sickened though it fascinated him. In that old-fashioned house on the hill he had lived since infancy. Indeed, he had known no other home, no other parent save the eccentric old professor, his uncle. On Thursday, the body of Prof. Arnold had been carried away and laid in another resting-place. Tonight the old home smoldered before him, a heap of blackening embers, wearing no vestige of resemblance to its beloved familiar contours. But little time was given him for meditation now.

"Oh, Mr. Robert!"

He felt his hands seized in a warm, strong grasp, which did not quickly loosen.

"Oh, Mr. Robert!" repeated Bertha, drawing him into the doorway of the bake-shop and beginning to cry. "I thought you were burned in the fire. Where have you been all the time?"

"Only at Miss Barlow's. How did it happen?"

"It was soon after you left. The library took fire. I heard Sire barking and ran down to find out what was the matter, when what should I see but the room full of smoke."

"Ellen is safe, I hope?"

"Ellen went out. We haven't seen her yet. But if it hadn't been for Sire——"

They had gone inside the shop and the great St. Bernard jumped up and fondled his young master joyfully, but again with that strange undertone in his barking, as of one who had a tale to tell, if only stupid men folk could understand it.

"What ails you, Sire? Poor fellow! Old master gone; house burned down; getting old yourself. Yes, it's too bad. Good dog."

Sire whined at the sympathy in Robert Floyd's voice.

"Nothing was saved?" asked the youth.

"Not a stitch. But I don't mind if I was only sure Ellen——"

"Are you really anxious about Ellen? I thought she went out?"

"Oh, yes. It was her day out. But when she came back to supper she ought to have looked for me."

"Perhaps she did hunt for you and missed you, or went to her sister's in the confusion. You haven't found a lodging yet yourself for the night?"

"I suppose I'll have to go to my aunt's."

"Mrs. Christenson's. That's the place for you; and take good care of Sire until I call for him."

"Go with Bertha, Sire," he commanded, but the dog had to be dragged away, the tall Swedish maiden laying her hand on his collar.

"Well, your house, as the little girl said in the story, presents a remarkable disappearance."

Robert turned toward the stranger who was so facetious out of season. Inspector McCausland had just parted company with the fire marshal and was sauntering carelessly about.

"How did it happen? Do they know yet?" asked Robert, anxiously.

"I don't," answered McCausland. "Possibly so"—he filliped off the lighted end of his cigar, but it fell into a black moat alongside of the curbstone and went out with a gentle hiss.

"But none of us smoked."

"Perhaps it was of incendiary origin," said the detective. "There have been some strange fires lately."

"It is a mystery," answered Robert Floyd.