to form a conclusion.

"And they did so. You cannot have forgotten the
singular knife which was found in the dead man's hand,
a knife which certainly no sane man would choose for a
weapon. It was, as Dr. Watson told us, a form of
knife which is used for the most delicate operations
known in surgery. And it was to be used for a
delicate operation that night. You must know, with
your wide experience of turf matters, Colonel Ross,
that it is possible to make a slight nick upon the
tendons of a horse's ham, and to do it subcutaneously,
so as to leave absolutely no trace. A horse so
treated would develop a slight lameness, which would
be put down to a strain in exercise or a touch of
rheumatism, but never to foul play."

"Villain! Scoundrel!" cried the Colonel.

"We have here the explanation of why John Straker
wished to take the horse out on to the moor. So
spirited a creature would have certainly roused the
soundest of sleepers when it felt the prick of the
knife. It was absolutely necessary to do it in the
open air."

"I have been blind!" cried the Colonel. "Of course
that was why he needed the candle, and struck the
match."