Every fall as Dia De Los Muertos approaches, monarch butterflies fly south across the border to Michoacan, Mexico. Many believe these butterflies embody the soul of their ancestors, returning back home to bask in the love of their families once again.

Although monarch butterflies have not yet visited the Mary Zepeda Native Plant Garden, the compact, meticulously designed space in Pilsen beckons them with open arms. Murals of monarch butterflies billowing triumphantly out of smokestacks plaster the walls. Patches of milkweed, the host plant of the monarch, are scattered around its crevasses.

On November 1st, in the heart of the garden, seven people, clutching photographs and miniature calacas, or Mexican skeletons, huddle around an altar, teetering on top of one of the protruding hills that freckle the area. This crowd is dedicating an ofrenda, or altar, to those who were killed or affected by the polluting fumes from Fisk, Pilsen’s recently shut down power plant. Erected by the Pilsen Environmental Rights and Reform Organization (PERRO), the ofrenda is a towering structure: layers of collages, replicas of neighboring buildings, paper flowers, and monarch butterflies envelop a tree emitting a cloud of leaves.

Jerry Mead-Lucero, PERRO organizer, beams at Luis Raul, who helped construct the structure. “The tree was a work of last minute innovation,” Mead-Lucero says. “We just found these branches from a bush in an abandoned lot.”

At the nearby Casa Michoacan, PERRO members sit in a circle with residents of Pilsen and discuss the meaning of Dia De Los Muertos, comments weaving between Spanish and English. The president of Casa Michoacan, Jose Luis Gutierrez, leads the discussion, hovering on the contrast between the European-born Halloween, which plays off fears and anxieties of death related to the shrinking harvest, and the Mexican holiday, which embraces death as “something more–an ascent into the next level.”

Another man describes in Spanish the ritual of preserving the soul of loved ones by decorating tombs with flowers, food, and Coronas. “The saddest thing,” he says, “is to see a tomb with nothing on it: it is a soul forgotten.”

The next day, PERRO and their ofrenda migrate to the 33rd annual Muertos De La Risa, an immense celebration and parade beginning at Dvorak Park. The ofrenda, balancing on the shoulders of vine-encrusted and skeleton-faced volunteers, nestles into a massive sea of flower-crowned calacas. Behind them, children from the ProsArts circus program skip in stilts. In front, the wings of giant cardboard monarch butterflies flap gently in the wind. The calacas and butterflies all flutter back into the park’s center, banners resembling the tissue paper papeles picados hanging from its roof. One particular banner, complete with a Dr. Seuss style illustration of gleeful monarchs circling a deflated smokestack, reads: “After suffocating so many for so long, the tower of power will finally belch its last cough.”