Therefore Simpson becomes eliminated from the case,
and our attention centers upon Straker and his wife,
the only two people who could have chosen curried
mutton for supper that night. The opium was added
after the dish was set aside for the stable-boy, for
the others had the same for supper with no ill
effects. Which of them, then, had access to that dish
without the maid seeing them?

"Before deciding that question I had grasped the
significance of the silence of the dog, for one true
inference invariably suggests others. The Simpson
incident had shown me that a dog was kept in the
stables, and yet, though some one had been in and had
fetched out a horse, he had not barked enough to
arouse the two lads in the loft. Obviously the
midnight visitor was some one whom the dog knew well.

"I was already convinced, or almost convinced, that
John Straker went down to the stables in the dead of
the night and took out Silver Blaze. For what
purpose? For a dishonest one, obviously, or why
should he drug his own stable-boy? And yet I was at a
loss to know why. There have been cases before now
where trainers have made sure of great sums of money
by laying against their own horses, through agents,
and then preventing them from winning by fraud.
Sometimes it is a pulling jockey. Sometimes it is
some surer and subtler means. What was it here? I
hoped that the contents of his pockets might help me