Today, just two distilleries produce absinthe in Pontarlier, though the town cherishes its history and association with the drink. During my trip in October, one of the main absinthe festivals — Les Absinthiades — was set to take place on the coming weekend. (Another festival, La Fête de l’Absinthe, recently took place in the Val-de-Travers town of Boveresse.) I had detected a rivalry between the two countries, and the Absinthiades seemed like a good chance to compare sides. After checking into a hotel and taking a walk around Pontarlier, I visited the town museum, which had an impressive exhibit on absinthe and the anti-absinthe hysteria that gripped Europe at the fin de siècle. Afterward, I found the Absinthiades in full swing at a small community hall, with a bustling bar serving numerous varieties of the drink. An interest in antiques and collectibles from the drink’s heyday makes up a large part of contemporary absinthe culture, and the hall featured a number of vendors hawking slotted absinthe spoons — used to sweeten the drink by melting the sugar under a stream of chilled water — as well as Art Nouveau water fountains, advertisements for extinct brands, and books on the history of the drink and its paraphernalia.

An American author, Scott MacDonald, was signing copies of his book, “Absinthe Antiques: a Collection From la Belle Époque,” when I asked if he could describe the difference between the two countries.

“The French are known for their vertes and the Swiss for the bleues,” he said. “The French absinthes tend to be darker and more mysterious. A good Swiss bleue is very pure and very clean.”

All absinthes seemed equally mysterious to me, producing the same intense reverie in my brain, although I was starting to think I preferred absinthe bleue in terms of taste. We talked about the two versions as we joined some of Mr. MacDonald’s friends on a walk across town to the Guy distillery, producer of François Guy absinthe.

Inside, small groups of French tourists lined up for samples of the distillery’s absinthe, as well as other spirits, including cherry-flavored kirsch and a local specialty scented with the buds of fir trees. In the courtyard outside the tasting room, several young absinthe fans — or absintheurs — debated the merits of Guy’s absinthe versus other brands, and I tried to follow their conversation in French.

A moment later, Mr. MacDonald approached with a glass. “Try this,” he said.

The drink seemed thicker, perhaps just in terms of the density of its aromas, with a long-lasting bitterness hiding behind a slightly oxidized, licorice-like anise nose. It was an absinthe verte, but the taste was more gentle than the others I’d tried, with an alcoholic warmth that seemed to expand into infinity.

I felt a strange sense of disappointment when Mr. MacDonald told me what I had just tried: one of the distillery’s own pre-ban absinthes, made just before the drink was outlawed in France in 1914, and poured from one of the last remaining bottles as a gift for Mr. MacDonald by the distillery’s owner. Until then, I thought that I had found what I was seeking on the route de l’absinthe, and that was Swiss absinthe bleue. But this had been one of the best sips of my life, and unfortunately I would almost certainly never taste anything like it again. Not even in the Val-de-Travers, beside a mountain spring, just a few steps ahead of the Green Fairy herself.