For rare book collectors, Mecca is Mexico City's Colonia Centro, and for such aficionados of mexicana as myself, its sanctum sanctorum, the Librería Madero—by the way, recently relocated from the Avenida Madero to the Avenida Isabela La Católica, facing the formidable wedding cake-white corner of the 16th century ex-convent of San Jerónimo, known today as the Claustro de Sor Juana, that is, the Convent of Sister Juana.

And if you would not know Sor Juana from a poinsettia, gentle reader, with all respect, you must crowbar out that boulder of ignorance, for which you will be rewarded by a glimpse of the diamond of the Mexico's Baroque period, the first great Latin American poet and playwright, "the Tenth Muse," a cloistered nun.

Texan poet John Campion was the first to translate Sor Juana's magnum opus, "Primero sueño," as "The Dream," in 1983. (Alas, that date is not a typo.) Campion's translation is out of print, but he offers a free PDF download of the text on his website, worldatuningfork.com. The first lines of Campion's translation beautifully capture Sor Juana's uncanny power:

Pyramidal
death-born shadow of earth
aimed at heaven
a proud point of vain obelisks
pretending to scale the Stars
.

In her time Sor Juana was one of the most learned individuals, man or woman, in the New World, and her prodigious oeuvre, from love poems to polemics, comedies to enigmas to plays to villancicos, was exceptionally sophisticated, so much so that its interpretation is today the province of a small army of sorjuanistas. As Mexico's Nobel laureate poet Octavio Paz writes in Sor Juana: Or, the Traps of Faith (translated by Margaret Sayers Peden), "A work survives its readers; after a hundred or two hundred years it is read by new readers who impose on it new modes of reading and interpretation. The work survives because of these interpretations, which are in fact resurrections."

And perchance startling discoveries. In his 2011 El eclipse del Sueño de Sor Juana, Américo Larralde Rangel makes a radiant case that her "Primero Sueño" describes the dawn over Mexico City after a lunar eclipse on the solstice of the winter of 1684.

In the Librería Madero I find on the first shelf, facing out, two new books by sorjuanistas: one about Sor Juana's family, another, just published by a Legionario de Cristo, that purports to decipher her twenty enigmas. The latter work incorporates a series of contemporary paintings of Sor Juana in the baroque style—dim backgrounds, crowns and scepters of flowers, and afloat above her head, fat-tummied cherubs, flounces, unspooling bundles of draperies. But these Sor Juanas look too pert, make too coy a tilt of the head. It seems to me as if, session over, the model might have just tossed off that habit to wriggle into some yoga wear.

Yes, just as in the United States, in Mexican cities yoga studios have been popping up like honguitos.

But if a vision of modern Mexico would have been obscure to Sor Juana, by no means is Sor Juana obscure in modern Mexico. She has inspired scores of poets and musicians; there have been movies, documentaries, and novels, most recently, Mónica Lavin's 2009 best-seller Yo, la peor (I, the Worst—yet to be translated into English-fingers crossed that Patricia Dubrava will do it).

As I write this in 2017, Sor Juana graces the celadon-green 200 peso bill, her portrait from the one by Miguel Cabrera in the Museo Nacional de Historia: a serenely intelligent young woman's face framed in a wimple, and behind her, her quills and inkpot and an open book of her poetry-and a few lines:

Hombres necios que acusáis
a la mujer sin razón,
sin ver que sois la ocasión
de lo mismo que culpáis.
.

I cannot pretend to render the music of Sor Juana's lines into English. But here's a rough go at their literal meaning: You pig-headed men who accuse women unjustly, blind to the fact that you are the cause for that which you cast blame.

All over the Mexican Republic— from Tijuana to Tampico, from Chiapas to Chihuahua, in cities as large as Monterrey and Veracruz, and from small towns such as Jalpan and Xilitla in the Sierra Gorda, to even tiny pueblitos on the far shores of the Baja California coast,— every day some gobsmacking number of 200 peso bills with Sor Juana's face and Sor Juana's poetry travel from palm to palm, wallet to cash register drawer, to back pocket, to purse, to cash register again, back to the bank and then counted out of teller's windows and spit out from ATMs, exchanged for tortas or tortillas, a taxi ride, a pair of jeans, a haircut, a costal of mangos. And for paper, pens, and books.

In her lifetime Sor Juana was also famous for the range and quality of her library. Near the end of her short life of 43 years, her confessor obliged her to give it up, and stop writing. She died in a plague, there behind the fortress-high walls of San Jerónimo, her claustro.

Sor Juana's end was so ghastly that until now, this balmy winter's day in 2017, I had never, in all my years in Mexico City, been able to bring myself to visit that claustro. From the Librería Madero, a copy of her genealogy under my arm, I follow the the convent's wall down the Avenida Isabela la Católica, and around the corner. Leaving my driver's license in exchange for a visitor's badge, I enter the Claustro de Sor Juana— now a university renowned for its cooking and hotel and restaurant management school and one of the first in Mexico to offer undergraduate and graduate degrees in creative writing. The students, shambling along affixed to their smartphones, could be students anywhere in Mexico: green hair, pink hair, jeans, T-shirts.

The university's central patio, vast as a stadium, once open-air, is covered with a sail-like white tent-roof. Other than that roof, and the unusually large proportions, and the tic-tac of a ping pong game, and the scattered tables of students slouching over their laptops and smart phones, this could be an ex-convent anywhere in Mexico, anywhere in Latin America or Spain. Arrayed like soldiers around this central patio, ground floor and second floor, are columns of grey stone, and behind them, evenly spaced, the wooden doors with their decorative iron medallions, to offices and class rooms. One of the ground floor doors stands out: it has mouldings of grey stone. This, according to the bronze plaque in the wall, was the cell of Sor Juana. Alas, closed for renovation.

A security guard directs me towards the chapel, where in the left wall of the auditorium, I can view Sor Juana's remains: A coffin behind glass. The coffin, too shiny-new to be the original, is topped with the figure-eight of a rope of wooden rosary beads. Above, the protective glass is etched with the words:

... triunfante quiero ver al que me mata
y mato a quien me quiere ver triunfante.
.

More or less: ... triumphantly I want to see the one who kills me and I kill the one who wants to see me triumphant. These lines are from Sor Juana's poem, "Cuál sea mejor, amar o aborrecer" ("Which is is better, to Love or Detest"). But listen to the music in her Spanish; note that repetition with variation, mata and then mato.

Sor Juana had what Spanish poet Federico García Lorca called duende. A Spanish-English dictionary will tell you that duende means genie, pixie, fairy, or sprite— but that is not what García Lorca meant in naming the special power of a great artist. García Lorca's duende is one of those words that gets hopelessly unwieldy in English. Here's my translation: A riff from Orpheus' lyre, a spinning chestahedron, a spadeful of soil from beneath pine duff, and as alchemical catalysts, a moonbeam and a sunbeam and three twinkles from Venus and Mars— then, a flamenco-move of a shove from behind.

I take a photo of Sor Juana's coffin with my smartphone. The photo comes out with my reflection, ghost-like, in the glass.

This is an excerpt from "Dispatch from the Sister Republic or, Papelito Habla" my long essay on the Mexican literary landscape and the power of the book.

Now available in Kindle.