“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.