This isn't a story about Chartreuse, but let's begin there.
In Voiron, near Grenoble in southeast France, Carthusian monks distill a liqueur from 130 medicinal herbs, roots and leaves. The recipe is a tightly guarded secret, known only to three holy brothers. It was conceived as an elixir of life, but so fine was the flavor that French toffs began drinking it with ice as a fancy digestif.
Chartreuse is a kaleidoscopic drink, sweet yet fiery, floral, minty and distinctly aniseedy; it is, said the stuttering Anthony Blanche in Evelyn Waugh's "Brideshead Revisited," like swallowing a sp-spectrum.