(FORTUNE Magazine) – What's bright green, tastes funny, may cause weird sensations and seizures if you're daring enough to drink it, and is suddenly showing up in all the really cool places these days? If you answered automotive antifreeze, you'd be correct, but you'd be revealing that you're something of a cultural clod. If you were a sensitive, avant-garde type, you'd know the hip answer is absinthe--an outlawed liqueur-with-a-kick that was banned almost everywhere about 80 years ago but is making a comeback in the U.S.

Absinthe was all the rage in Paris cafe society at the turn of the century. Its popularity was due not only to its 150-proof alcohol content but also to its inclusion of an extract of a weedy plant called wormwood, which contains a mildly hypnotic drug called thujone. Around 1915 absinthe was outlawed in most countries, including the U.S., because wormwood was thought to cause convulsions and neurological damage. Even Vincent van Gogh's madness was ascribed to his fondness for the stuff. But a few countries, notably Czechoslovakia, didn't bother to ban it, and enterprising locals have continued to make small batches. With the fall of communism, tourists swarmed to Prague and rediscovered absinthe. When they returned home and researched it on the Internet, they found Czech-based capitalists eager to ship them some--illegally, of course. Kyle Bairnsfather, an American who worked in Eastern Europe as a Peace Corps volunteer, returned to the Czech Republic to sell absinthe. He refers to the liqueur (ironically, perhaps) as "insanely popular" and says he's shipping 3,500 bottles a month, mostly to the U.S., England, and Ireland.

Now absinthe is showing up in all the trendy places you might expect. One liquor store owner in Manhattan says twentysomethings sample it at nightclubs and show up at his shop the next morning with the word "absinthe" written on a piece of paper, thinking that having some will make them irresistibly cool. Adding to absinthe's exotic allure are the rituals and paraphernalia associated with it: the thick glass goblet, the elaborate slotted spoon to hold a sugar cube as ice water is poured over it, and the mysterious change in color from garish green to milky as water is added.

The world hardly needs another mind-altering chemical in the food supply, but it is difficult to know just how dangerous absinthe is. The Food and Drug Administration bans thujone as a harmful food additive, not as a controlled dangerous substance. Absinthe's defenders say it got its bad reputation at the turn of the century because some manufacturers added dangerous chemicals, including copper sulfate, to make it green. Others argue that given absinthe's high alcohol content, you will probably die of liver disease long before the wormwood does you in. Wormwood in high doses, though, is truly dangerous. Its extract is sold as a massage oil, and some genius in California drank several grams of it a few years ago. He nearly died of kidney failure.

It's hard to believe that an absinthe craze will sweep the nation. The stuff tastes terrible, like a mix of licorice and Vicks VapoRub. (Indeed, wormwood oil got its name because it was used to purge intestinal worms.) Maybe absinthe doesn't make you crazy. Maybe you just have to be crazy to like it.

--Brian O'Reilly