any of the servants met with an accident?"
"No, none. Neither dog, nor cat, nor any other pet was kept, thereforethe stain upon the mat was unaccountable. It was that fact which causedme, greatly against Miss Ethelwynn's consent, to seek a locksmith andtake down the two locked doors of the laboratory."
And he paused, gazing once more straight into the flames, with a curiousexpression in those deep-set brown eyes.
"And what did you find?" I eagerly inquired.
"I discovered the truth," he said in a hard, changed tone. "The doorsgave us a good deal of trouble. At the end of the laboratory, huddledin a corner, was the body of the Professor. He had been stabbed to theheart, while his face presented a horrible sight, the features havingbeen burned almost beyond recognition by some terribly corrosive fluid--a crime which in every phase showed itself to be due to some fiendishspirit of revenge."
"But that is most extraordinary!" I gasped, staring at the speaker."The sleeping-car conductor took him to Edinburgh! Besides, how couldthe two doors be locked behind the assassin? Were the keys still uponthe victim?"
"They are still upon the dead man's watch-chain," he said. "But, markyou, there is still a further feature of mystery in the affair. Afterher father's departure for the station, his daughter put on adressing-gown and, sending Morgan to bed, seated herself in herarm-chair before the fire in the Red Room, or boudoir, and took a novel.She read until past four o'clock, being in the habit of reading atnight, and then, not being sleepy, sat writing letters until adrowsiness fell upon her. She did not then awake until a maid enteredat seven to draw up the blinds."
"Then she was actually at the only entrance to the laboratory all thenight!"
"Within a yard and a half of it," said Kershaw Kirk. "But the affairpresents many strange features," he went on. "The worst feature of itall, Mr. Holford, is that a motive--a very strong motive--is known tocertain persons why I myself should desire to enter that laboratory.Therefore I must be suspected of the crime, and--well, I admit at onceto you I shall be unable to prove an alibi!"
I was silent for a moment.
"Unable to prove an alibi!" I echoed. "But the police have as yet noknowledge of the affair," I remarked.
"No; I have, however, reported it in another quarter. It's a mostserious matter, for I have suspicion that certain articles have beenabstracted from the laboratory."
"And that means--what?"
"It means, my dear sir, very much more than you ever dream. This is atonce the strangest and the most serious crime that has been committed inEngland for half a century. You are a man of action and of honour, Mr.Holford. Will you become my friend, and assist me in trying to unravelit?" he asked quickly, bending forward to me in his earnestness.
"Most certainly I will," I replied, fascinated by the amazing story hehad just related, quite regardless of the fact that he was the suspectedassassin.
I wonder whether if I had known into what a vortex of dread, suspicion,and double-dealing that decision of mine would have led me I would haveso lightly consented to render my help?
I think not.
"Well," he said, glancing at his watch, "the place has not been touched.If you consent to help me, it would be best that you saw it and formedyour own independent theory. Would you care to come with me now? Youcould run along and make some excuse to Mrs. Holford."
The remarkable mystery, surrounding as it did one of the best-knownscientists in the land, had already gripped my senses. Therefore I didas he suggested, and about an hour later alighted from one of my owncars at the portico of that house of tragedy.
A white-faced, grave-eyed man in black, the man Antonio, opened the doorin response to our ring, but on recognising my companion he gripped himquickly by the arm, gasping:
"Ah, signore, I had just telephoned to you! I had no idea you werereturning here to-night. Madonna Santa, signore, it's terrible--terrible! Something else has happened. The young lady--she's--"
"What do you mean? What has happened now?" asked Kirk quickly. "Tellme; she's--what?"
But the old Italian could not speak, so overcome and scared was he. Heonly pulled my companion forward into the dining-room on the left, andwith his thin, bony finger pointed within.
And as I entered the big room my eyes fell upon a sight that staggeredme.
Like the old servant, I, too, stood aghast.
Truly Kershaw Kirk had spoken the truth when he had said that themystery was no ordinary one.
At that moment the problem seemed to me to be beyond solution. Italready ranked in my mind as one of those mysteries to which the key isnever discovered. Who _did_ kill Professor Greer?
CHAPTER THREE.
THE HOUSE OF MYSTERY.
What I saw in the house of Professor Greer on the night of thatfifteenth of January formed indeed a strange and startling spectacle.
Ah, I am haunted by it even now!
That sallow-faced man who had conducted me there was himself a mystery,and upon his own confession was suspected of a foul crime. Besides, itwas being kept rigorously from the police, which, to say the least, wasa proceeding most unusual.
What could it all mean? Who was this Kershaw Kirk, this "dealer insecrets," as he called himself, who was immune from public trial, eventhough not immune from arrest and imprisonment? The whole intricateproblem launched upon me during those past few hours held me infascination as nothing had ever held me before.
I could see that the man Antonio held Mr. Kirk in great fear or greatregard, for he was urbanity itself.
But what we saw within the fine, solidly-furnished dining-room, with itscarved buffet filled with antique shining silver, was so unexpected thateven my companion gave vent to an exclamation of amazement. Upon thedark carpet near the empty grate, her head pillowed upon a yellow silkencushion, lay a very pretty, fair-haired girl of about twenty-two. Herhat was off, otherwise she was in walking dress, with a short fur jacketand a fine blue fox boa, which, loosened, showed the delicacy of herwhite throat. Her face contour was bloodless; but all one side of herface was swollen, disfigured, and white as marble.
"Great heavens!" cried Kirk, as he fell on his knees beside her andgrasped her hands. "Why, look! She's been disfigured, just as herfather has been!" And he bent until his ear was against her heart.
"Get me that little mirror from the wall--over there, Mr. Holford.Quick!" he urged.
I sprang to do his bidding, and he placed against her mouth the littlecarved bracket wherein the square of looking-glass was set. When hewithdrew it, it was unclouded.
"She may not be dead?" I exclaimed. "Shall I go for a doctor?"
"No," Kirk snarled; "we want no doctors poking their noses about here.This is a matter which concerns only myself, Mr. Holford!" And he bentto the prostrate girl to make a more minute investigation in a mannerwhich showed me that he understood the various symptoms of death.
"As you know, signore," Antonio said, "Miss Ethelwynn left last night tostay at her aunt's, Lady Mellor's, in Upper Brook Street, and I have notseen her since, until ten minutes ago I chanced to enter here, when, tomy amazement, I found her lying just as you see her, except that I putthe pillow beneath her head before telephoning for you. I didn't knowwhom to call."
"You've told no one else of this?" Kirk asked quickly.
"Only my brother, signore. He's staying with me. The girls have allleft, and Morgan, Miss Ethelwynn's maid, is at Lady Mellor's."
"Your brother!" repeated Kirk reflectively.
"Yes, signore. He's here." And a respectably-dressed man a trifleyounger than Antonio, who had been standing out in the hall, entered andbowed. "Pietro keeps a tobacconist's in the Euston Road," he explained."I asked him here, as I don't care to stay in this place alone justnow."
Kirk regarded the new-comer keenly, but made no remark. His attentionwas upon the unfortunate girl, who as far as we could gather, hadreturned in secret, entered quietly with her latch-key, and removed herhat, placing it upon the couch,
sticking its pins through it, before shehad been struck down by some unseen hand.
There was no perceptible wound, and Kirk could not determine whether shewas still alive, yet he refused to summon medical aid. I confess tobeing somewhat annoyed at his obstinacy, and surprised at the secrecywith which he treated the whole of the remarkable circumstances. Thatvery fact tended to strengthen the suspicion that he himself knew moreabout the crime than he had admitted.
Surely the police should be informed!
He was very carefully examining the girl's clothing, seeking to discovera wound; but, as far as we could see, there was none, yet the pallor ofthe countenance was unmistakably that of death, while the hard, whitedisfigurement of