"Yes, the hoot of an owl."
"Are you sure? It doesn't sound natural to me."
"What do you say it is, then? A signal?"
"I'm certain of it."
Jorancé reflected:
"After all, it's quite possible ... some smuggler perhaps.... But it's a bad moment to have chosen."
"Why?"
"Well, now that the German post has been cut down, it's likely that all this part of the frontier is being more closely watched than usual."
"Yes, of course," said Morestal. "Still, that owl's hoot ..."
There was a short slope and then they emerged upon a higher upland, surrounded by enormous fir-trees, which formed a sort of rampart. This was the Butte-aux-Loups. The road cut it in two; and the posts of each country stood facing each other.