icent scope. St. Claude, of which Leroux had just spoken as the
place where M. Aristide Fournier had recently bought himself a house,
is in France, only a few kilometres from the neutral zone of Gex. It
seemed a strange spot to choose for a wealthy and fashionable member
of Parisian bourgeois society, I was bound to admit.

"But," I mused, "one cannot go to Gex without a permit from the
police."

"Not by road," Leroux assented. "But you will own that there are means
available to men who are young and vigorous like M. Fournier, who
moreover, I understand, is an accomplished mountaineer. You know Gex,
of course?"

I had crossed the Jura once, in my youth, but was not very intimately
familiar with the district. Leroux had a carefully drawn-out map of it
in his pocket; this he laid out before me.

"These two roads," he began, tracing the windings of a couple of thin
red lines on the map with the point of his finger, "are the only two
made ones that lead in and out of the district. Here is the
Valserine," he went on, pointing to a blue line, "which flows from
north to south, and both the roads wind over bridges that span the
river close to our frontier. The French customs stations are on our
side of those bridges. But, besides those two roads, the frontier can,
of course, be crossed by one or other of the innumerable mountain
tracks which are only accessible to pedestrians or mules. That is
where our customs officials are powerless, for the tracks are
precipitous and offer unlimited cover to those who know every inch of
the ground. Several of them lead directly into St. Claude, at some
considerable distance from the customs stations, and it is these
tracks which are being used by M. Aristide Fournier for the felonious
purpose of trading with the enemy--on this I would stake my life. But
I mean to be even with him, and if I get the help which I require from
you, I am convinced that I can lay him by the heels."

"I am your man," I concluded simply.

"Very well," he resumed. "Are you prepared to journey with me to Gex?"

"When do you start?"

"To-day."

"I shall be ready."

He gave a deep sigh of satisfaction.

"Then listen to my plan," he said. "We'll journey together as far as
St. Claude; from there you will push on to Gex, and take up your abode
in the city, styling yourself an interpreter. This will give you the
opportunity of mixing with some of the smuggling fraternity, and it
will be your duty to keep both