piece of chalk, drew a
white cross, surrounded by a circle, on the wall of the house next to
him.

The two continued on their way. A minute later, a fresh halt. The
strange individual picked up a pin and dropped a piece of orange-peel;
and the boy at once made a second cross on the wall and again drew a
white circle round it.

"By Jove!" thought the chief-inspector, with a grunt of satisfaction.
"This is rather promising.... What on earth can those two merchants be
plotting?"

The two "merchants" went down the Avenue Friedland and the Rue du
Faubourg-Saint-Honore, but nothing occurred that was worthy of special
mention. The double performance was repeated at almost regular intervals
and, so to speak, mechanically. Nevertheless, it was obvious, on the one
hand, that the man with the orange-peel did not do his part of the
business until after he had picked out with a glance the house that was
to be marked and, on the other hand, that the boy did not mark that
particular house until after he had observed his companion's signal. It
was certain, therefore, that there was an agreement between the two; and
the proceedings presented no small interest in the chief-inspector's
eyes.

At the Place Beauveau the man hesitated. Then, apparently making up his
mind, he twice turned up and twice turned down the bottom of his
trousers legs. Hereupon, the boy sat down on the curb, opposite the
sentry who was mounting guard outside the Ministry of the Interior, and
marked the flagstone with two little crosses contained within two
circles. The same ceremony was gone through a little further on, when
they reached the Elysee. Only, on the pavement where the President's
sentry was marching up and down, there were three signs instead of two.

"Hang it all!" muttered Ganimard, pale with excitement and thinking, in
spite of himself, of his inveterate enemy, Lupin, whose name came to his
mind whenever a mysterious circumstance presented itself. "Hang it all,
what does it mean?"

He was nearly collaring and questioning the two "merchants." But he was
too clever to commit so gross a blunder. The man with the orange-peel
had now lit a cigarette; and the boy, also placing a cigarette-end
between his lips, had gone up to him, apparently with the object of
asking for a light.

They exchanged a few words. Quick as thought, the boy handed his
companion an object which looked--at least, so the inspector
believed--like a revolver. They both bent o