floor. "We must consider whether we'll pull the whole place to pieces to see what it's made of."
"I'm coming in a minute," said the voice from the ledge above their heads, a voice somewhat suggestive of an articulate yawn.
"What are you waiting for?" asked Sir Walter, impatiently. "Can you see anything there?"
"Well, yes, in a way," replied the voice, vaguely. "In fact, I see it quite plain now."
"What is it?" asked Wilson, sharply, from the table on which he sat kicking his heels restlessly.
"Well, it's a man," said Horne Fisher.
Wilson bounded off the table as if he had been kicked off it. "What do you mean?" he cried. "How can you possibly see a man?"
"I can see him through the window," replied the secretary, mildly. "I see him coming across the moor. He's making a bee line across the open country toward this tower. He evidently means to pay us a visit. And, considering who it seems to be, perhaps it would be more polite if we were all at the door to receive him." And in a leisurely manner the secretary came down the ladder.
"Who it seems to be!" repeated Sir Walter in astonishment.
"Well, I think it's the man you call Prince Michael," observed Mr. Fisher, airily. "In fact, I'm sure it is. I've seen the police portraits of him."
There was a dead silence, and Sir Walter's usually steady brain seemed to go round like a windmill.
"But, hang it all!" he said at last, "even supposing his own explosion could have thrown him half a mile away, without passing through any of the windows, and left him alive enough for a country walk—even then, why the devil should he walk in this direction? The murderer does not generally revisit the scene of his crime so rapidly as all that."
"He doesn't know yet that it is the scene of his crime," answered Horne Fisher.
"What on earth do you mean? You credit him with rather singular absence of mind."
"Well, the truth is, it isn't the scene of his crime," said Fisher, and went and looked out of the window.
There was another silence, and then Sir Walter said, quietly: "What sort of notion have you really got in your head, Fisher? Have you developed a new theory about how this fellow escaped out of the ring round him?"
"He never escaped at all," answered the man at the window, without turning round. "He never escaped out of the ring because he was never inside the ring. He was not in this tower at all, at least not when we were surrounding it."
He turned and leaned back against the window, but, in spite of his usual listless manner, they almost fancied that the face in shadow was a little pale.
"I began to guess something of the sort when we were some way from the tower," he said. "Did you notice that sort of flash or flicker the candle gave before it was extinguished? I was almost certain it was only the last leap the flame gives when a candle burns itself out. And then I came into this room and I saw that."
He pointed at the table and Sir Walter caught his breath with a sort of curse at his own blindness. For the candle in the candlestick had obviously burned itself away to nothing and left him, mentally, at least, very completely in the dark.
"Then there is a sort of mathematical question," went on Fisher, leaning back in his limp way and looking up at the bare walls, as if tracing imaginary diagrams there. "It's not so easy for a man in the third angle to face the other two at the same moment, especially if they are at the base of an isosceles. I am sorry if it sounds like a lecture on geometry, but——"
"I'm afraid we have no time for it," said Wilson, coldly. "If this man is really coming back, I must give my orders at once."
"I think I'll go on with it, though," observed Fisher, staring at the roof with insolent serenity.
"I must ask you, Mr. Fisher, to let me conduct my inquiry on my own lines," said Wilson, firmly. "I am the officer in charge now."
"Yes," remarked Horne Fisher, softly, but with an accent that somehow chilled the hearer. "Yes. But why?"
Sir Walter was staring, for he had never seen his rather lackadaisical young friend look like that before. Fisher was looking at Wilson with lifted lids, and the eyes under them seemed to have shed or shifted a film, as do the eyes of an eagle.
"Why are you the officer in charge now?" he asked. "Why can you conduct the inquiry on your own lines now? How did it come about, I wonder, that the elder officers are not here to interfere with anything you do?"
Nobody spoke, and nobody can say how soon anyone would have collected his wits to speak when a noise came from without. It was the heavy and hollow sound of a blow upon the door of the tower, and to their shaken spirits it sounded strangely like the hammer of doom.
The wooden door of the tower moved on its rusty hinges under the hand that struck it and Prince Michael came into the room. Nobody had the smallest doubt about his identity. His light clothes, though frayed with his adventures, were of fine and almost foppish cut, and he wore a pointed beard, or imperial, perhaps as a further reminiscence of Louis Napoleon; but he was a much taller and more graceful man that his prototype. Before anyone could speak he had silenced everyone for an instant with a slight but splendid gesture of hospitality.
"Gentlemen," he said, "this is a poor place now, but you are heartily welcome."
Wilson was the first to recover, and he took a stride toward the newcomer.
"Michael O'Neill, I arrest you in the king's name for the murder of Francis Morton and James Nolan. It is my duty to warn you——"
"No, no, Mr. Wilson," cried Fisher, suddenly. "You shall not commit a third murder."
Sir Walter Carey rose from his chair, which fell over with a crash behind him. "What does all this mean?" he called out in an authoritative manner.
"It means," said Fisher, "that this man, Hooker Wilson, as soon as he had put his head in at that window, killed his two comrades who had put their heads in at the other windows, by firing across the empty room. That is what it means. And if you want to know, count how many times he is supposed to have fired and then count the charges left in his revolver."
Wilson, who was still sitting on the table, abruptly put a hand out for the weapon that lay beside him. But the next movement was the most unexpected of all, for the prince standing in the doorway passed suddenly from the dignity of a statue to the swiftness of an acrobat and rent the revolver out of the detective's hand.
"You dog!" he cried. "So you are the type of English truth, as I am of Irish tragedy—you who come to kill me, wading through the blood of your brethren. If they had fallen in a feud on the hillside, it would be called murder, and yet your sin might be forgiven you. But I, who am innocent, I was to be slain with ceremony. There would be long speeches and patient judges listening to my vain plea of innocence, noting down my despair and disregarding it. Yes, that is what I call assassination. But killing may be no murder; there is one shot left in this little gun, and I know where it should go."
Wilson turned quickly on the table, and even as he turned he twisted in agony, for Michael shot him through the body where he sat, so that he tumbled off the table like lumber.
The
