er placidly, "if we only had an idea of
where we were going."

"Well, where are you going?" asked the other, staring.

Valentin smoked frowningly for a few seconds; then, removing his
cigarette, he said: "If you know what a man's doing, get in front of
him; but if you want to guess what he's doing, keep behind him. Stray
when he strays; stop when he stops; travel as slowly as he. Then you may
see what he saw and may act as he acted. All we can do is to keep our
eyes skinned for a queer thing."

"What sort of queer thing do you mean?" asked the inspector.

"Any sort of queer thing," answered Valentin, and relapsed into
obstinate silence.

The yellow omnibus crawled up the northern roads for what seemed like
hours on end; the great detective would not explain further, and perhaps
his assistants felt a silent and growing doubt of his errand. Perhaps,
also, they felt a silent and growing desire for lunch, for the hours
crept long past the normal luncheon hour, and the long roads of the
North London suburbs seemed to shoot out into length after length like
an infernal telescope. It was one of those journeys on which a man
perpetually feels that now at last he must have come to the end of the
universe, and then finds he has only come to the beginning of Tufnell
Park. London died away in draggled taverns and dreary scrubs, and then
was unaccountably born again in blazing high streets and blatant hotels.
It was like passing through thirteen separate vulgar cities all
just touching each other. But though the winter twilight was already
threatening the road ahead of them, the Parisian detective still sat
silent and watchful, eyeing the frontage of the streets that slid by on
either side. By the time they had left Camden Town behind, the policemen
were nearly asleep; at least, they gave something like a jump as
Valentin leapt erect, struck a hand on each man's shoulder, and shouted
to the driver to stop.

They tumbled down the steps into the road without realising why they
had been dislodged; when they looked round for enlightenment they found
Valentin triumphantly pointing his finger towards a window on the left
side of the road. It was a large window, forming part of the long
facade of a gilt and palatial public-house; it was the part reserved for
respectable dining, and labelled "Restaurant." This window, like all the
rest along the frontage of the hotel, was of frosted and figured glass;
but in the middle of it was a bi