“Suppose, now, that you have succeeded in putting the cart before the horse, Mr. Narkom,” Cleek said suddenly, “you proceed to give me, not the ramifications of the case, but the case itself. You have repeatedly spoken of the murder having taken place in some place which is difficult of access and under most mystifying circumstances. Now, if you don’t mind, I should like to hear what those circumstances are.”

“All right, old chap, I’ll give you the details as briefly as possible. In the first place, you must know that Heatherington Hall is a very ancient place, dating back, indeed, to those pleasant times when a nobleman’s home had to be something of a fortress as well, if he didn’t want to wake up some fine morning and find his place ‘sacked,’ his roof burnt over his head, and himself and his lady either held for ransom or freed from any possibility of having ‘headaches’ thereafter. Now, a round tower with only one door by which to enter, and no windows other than narrow slits, through which the bowmen could discharge their shafts at an attacking party without exposing themselves to the dangers of a return fire, was the usual means of defence adopted—you’ll see dozens of them in Suffolk, dear chap, but whether for reasons of economy or merely to carry out some theory of his own, the first lord of Heatherington Hall did not stick to the general plan.

“In brief, instead of building a tall tower rising from the ground itself, he chose to erect upon the roof of the west wing of the building a lower but more commodious one than was customary. That is to say, that while his tower was less than half the height of any other in the country, its circumference was twice as great, and, by reason of the double supply of bowman’s slits, equally as effective in withstanding a siege; and, indeed, doubly difficult to assault, as before an invading force could get to the door of the place it would have to fight its way up through the main building to reach the level of it.

“Now, owing to the peculiarity of its construction—it is not more than eighteen feet high—the fact that it contained but one circular room, and all those bowman slits in the walls of it, this unusual ‘tower’ gained an equally unusual name for itself, and became known everywhere as the ‘Stone Drum of Heatherington,’ and is even mentioned by that name in the Inquisitio Eliensis of the “Domesday Book,” which, as you doubtless know, is the particular volume of that remarkable work which records the survey, et cetera, of the counties of Cambridge, Hertford, Essex, Norfolk, Suffolk, and Huntingdon.”

“I see,” said Cleek, with an amused twinkle in his eye. “You are getting on, Mr. Narkom. We shall have you lecturing on archÆology one of these fine days. But to return to our mutton—or, rather, our stone drum—was it in that place, then, that the murder was committed?”

“Yes. It is one of the few, very few, parts of the building to which Mr. Jefferson P. Drake did nothing in the way of modernizing, and added nothing in the way of ’improvements.’ That, probably, was because, as it stood, it offered him a quiet, secluded, and exclusive retreat for the carrying on of his experiments; for wealth had brought with it no inclination to retire, and he remained to the last in the lists of the world’s active forces. As a general thing, he did not do much in the way of burning the midnight oil, but conducted most of his experiments in the daytime. But last night was an exception. It may be that the news of his son’s appeal to the lodgekeeper that afternoon had upset him, for he was restless and preoccupied all the evening, Lord Fallowfield says—or, at least, so young Drake reports him as having said—and instead of retiring with the rest of the house party when bedtime came and his Japanese valet carried up his customary carafe of ice-water——”

“Oh, he has a Japanese valet, has he? But, of course, in these days no American gentleman with any pretence to distinction whatsoever would be without one. Go on, please. His Japanese valet carried up the ice-water, and—then what?”

“Then he suddenly announced his intention of going into the Stone Drum and working for a few hours. Lord Fallowfield, it appears, tried his best to dissuade him, but to no purpose.”

“Why did he do that? Or don’t you know?”

“Yes. I asked that very question myself. I was told that it was because his lordship saw very plainly that he was labouring under strong mental excitement, and he thought that rest would be the best thing for him in the circumstances. Then, too, his lordship and he are warmly attached to each other. In fact, the earl was as fond of him as if he had been a brother. As well he ought to be, by James! when you recollect that before he got the idea into his head of marrying his son to Lady Marjorie he added a codicil to his will bequeathing the place to Lord Fallowfield, together with all the acres and acres of land he had added to it, and all the art treasures he had collected, absolutely free from death duties.”

“Oho!” said Cleek, then smiled and pinched his chin and said no more.

“Well, it appears that when his lordship found that he couldn’t make the stubborn old johnnie change his mind, he accompanied him to the Stone Drum, together with the valet, to see that everything was as it should be, and that nothing was wanting that might tend to the comfort and convenience of a night worker. When there was nothing more that could be done, the valet was dismissed, his lordship said good-night to his friend and left him there alone, hearing, as he passed along the railed walk over the roof of the wing to the building proper (a matter of some twenty-odd feet) the sound of the bolt being shot, the bar put on, and the key being turned as Mr. Drake locked himself in.

“What happened from that moment, Cleek, nobody knows. At seven o’clock this morning the valet, going to his master’s room with his shaving-water, found that he had never gone to bed at all, and, on hastening to the Stone Drum, found that a light was still burning within and faintly illuminating the bowman’s slits; but although he knocked on the door and called again and again to his master, he could get no answer. Alarmed, he aroused the entire household; but despite the fact that a dozen persons endeavoured to get word from the man within, not so much as a whisper rewarded them. The bolt was still ‘shot,’ the bar still on, the key still turned on the inner side of the door, so they could force no entry to the place; and it was never until the village blacksmith had been called in and his sledge had battered down the age-weakened masonry in which that door was set that any man knew for certain what that burning light and that unbroken silence portended. When, however, they finally got into the place there lay the once famous inventor at full length on the oaken floor close to the barred door, as dead as George Washington, and with never a sign of what killed him either on the body or in any part of the place. Yet the first look at his distorted features was sufficient to prove that he had died in agony, and the position of the corpse showed clearly that when the end came he was endeavouring to get to the door.”“Heart failure, possibly,” said Cleek.

“Not a hope of it,” replied Narkom. “A doctor was sent for immediately; fortunately one of the most famous surgeons in England happened to be in the neighbourhood at the time—called down from town to perform an operation. He is willing, so young Mr. Drake tells me, to stake his professional reputation that the man’s heart was as sound as a guinea; that he had not imbibed one drop of anything poisonous; that he had not been asphyxiated, as, of course, he couldn’t have been, for the bowman’s slits in the wall gave free ventilation to the place, if nothing more; that he had not been shot, stabbed, or bludgeoned, but, nevertheless, he had died by violence, and that violence was not, and could not be, attributed to suicide, for there was everything to prove to the contrary. In short, that whatever had attacked him had done so unexpectedly and while he was busy at his work-table, for there was the chair lying on its back before it, just as it had fallen over when he jumped up from his seat, and there on the ‘working plan’ he was drawing up was the pen lying on a blob of India ink, just as it had dropped from his hand when he was stricken. Some murderous force had entered that room, and passed out of it again, leaving the door barred, bolted, and locked upon the inside. Some weapon had been used, and yet no weapon was there and no trace upon the body to indicate what its character might be. Indeed, everything in the room was precisely as it had been when Lord Fallowfield walked out last night and left him, beyond the fact of the overturned chair and a little puddle of clear water lying about a yard or so from the work-table and, owing to the waxing and polishing, not yet absorbed by the wood of the floor. As no one could account for the presence of that, and as it was the only thing there which might offer a possible clue to the mystery, the doctor took a small sample of that water and analyzed it. It was simply plain, everyday, common, or garden pure water, and nothing more, without the slightest trace of any foreign matter or of any poisonous substance in it whatsoever. There, old chap, that’s the ‘case’—that’s the little riddle you’re asked to come down and solve. What do you make of it, eh?”

“Tell you better when I’ve seen Mr. James Drake and Lord Fallowfield and—the doctor,” said Cleek, and would say no more than that for the present.