And then there's the jackpot: an entire stall given over to Santa Muerte devotion. Here, devotees of (as she is variously known) "La Madrina" ("the Godmother"), "La Flaka" (a slang spelling for "the Skinny Woman") or "La Niña Blanca" ("the White Lady") can buy candles, statues, posters and amulets for her veneration.
The stallholders — Jonathan Mejia and Eduardo Mora, two men who look no older than 20 — say she grants many wishes, in many different areas of life. All you have to do is ask, light the right color of candle to her and then make a sacrifice. (You also need to make sure Santa Muerte is wearing a matching-color robe, though adherents say this is less important than the correct color of candle.)
"I don't know all the colors, but red is for love. You give her wine, money, food," says Mora. "Gold is for money, green is for health."
Asked about the supposedly death-dealing black candle, the one that can be used to wreak vengeance and downfall on your enemies, Mora shrugs. "I don't know about that. We do run out of them fast." (Police say that black candles are found far more often in the private shrines of drug dealers and assassins than they are at Santa Muerte's increasingly common public altars.)
And it's not just enemies from whom Santa Muerte can extract a heavy toll, even the ultimate price.
"There's a downside," Mejia says. "When you ask her for something, you have to promise her something. If you don't make that promise, um...many people say she takes away one of your loved ones."
In the last ten years, this harshest of all mistresses has come gliding inexorably from the shadows of Mexican folk religion, far from what scholars believe was her birthplace on or near Mexico's central Gulf Coast. As recently as 12 years ago, most Mexicans had never heard of her, but now her cult is spreading beyond the borders of that country, both south to Central America and north to the United States, where one expert tells us that some of her adherents today are white and black Anglos.
In spite of official rejection by the highest levels of the Roman Catholic Church in Mexico, Santa Muerte's followers only increase in number and devotion, carrying her all the way onto the fringes of the American pop-culture mainstream. She made a cameo on Breaking Bad — Tuco's terrifying cousins light candles to her, petitioning her for success on the way to Albuquerque on their mission of murderous revenge.
The faithful adore her publicly at shrines all over Mexico. People pray to her on her Facebook page, and there are drives afoot in several cities, Houston included, to raise funds to build permanent public chapels in her honor. Houstonians can buy her votive candles not just at barrio yerberíasand botánicas, but also at their friendly neighborhood Fiesta supermarket or Dollar Tree store.
Mexican bishops have said her veneration is akin to Satanism, and Mexican prosecutors claim that Santa Muerte has been linked to cartel-related human sacrifices.
Others say her scythe is not just a weapon but also a shield: They see her as a bringer of comfort in dark times, a beacon of peace in dark times.
One thing is for sure: Santa Muerte is here to stay. Some concerned Catholics even believe that she is at war with Our Lady of Guadalupe herself for status as unofficial queen of Mexican souls.