It certainly was uncommonly
hard, he thought, as he paced the cricket field after leaving Sergeant
Collard, to detect anybody, unless you knew who had really done the
crime. As he brooded over the case in hand, his sympathy for Dr.
Watson increased with every minute, and he began to feel a certain
resentment against Sir Arthur Conan Doyle. It was all very well for
Sir Arthur to be so shrewd and infallible about tracing a mystery to
its source, but he knew perfectly well who had done the thing before
he started!

Now that he began really to look into this matter of the alarm bell
and the painting of Sammy, the conviction was creeping over him that
the problem was more difficult than a casual observer might imagine.
He had got as far as finding that his quarry of the previous night was
a boy in Mr. Outwood's house, but how was he to get any farther? That
was the thing. There were, of course, only a limited number of boys in
Mr. Outwood's house as tall as the one he had pursued; but even if
there had been only one other, it would have complicated matters. If
you go to a boy and say, "Either you or Jones were out of your house
last night at twelve o'clock," the boy does not reply, "Sir, I cannot
tell a lie--I was out of my house last night at twelve o'clock." He
simply assumes the animated expression of a stuffed fish, and leaves
the next move to you. It is practically Stalemate.

All these things passed through Mr. Downing's mind as he walked up and
down the cricket field that afternoon.

What he wanted was a clue. But it is so hard for the novice to tell
what is a clue and what isn't. Probably, if he only knew, there were
clues lying all over the place, shouting to him to pick them up.

What with the oppressive heat of the day and the fatigue of hard
thinking, Mr. Downing was working up for a brain-storm, when Fate once
more intervened, this time in the shape of Riglett, a junior member of
his house.

Riglett slunk up in the shamefaced way peculiar to some boys, even
when they have done nothing wrong, and, having capped Mr. Downing with
the air of one who has been caught in the act of doing something
particularly shady, requested that he might be allowed to fetch his
bicycle from the shed.

"Your bicycle?" snapped Mr. Downing. Much thinking had made him
irritable. "What do you want with your bicycle?"

Riglett shuffled, stood first on his left foot, then on his right,
blushed, and finally remarked, as if it were