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