After years of painstaking excavation, López Luján and his crew have discovered, in a deep pit beside the monolith, some of the most exotic Aztec offerings ever found. Removing a stucco patch in the plaza floor, the excavators came upon 21 white flint sacrificial knives painted red: the teeth and gums of the Aztec earth monster, her mouth open wide to receive the dead. They dug deeper and found a bundle wrapped in agave leaves. It contained an assortment of sacrificial perforators made of jaguar bone, used by Aztec priests to spill their own blood as a gift to the gods.
Alongside the perforators were bars of copal—priestly incense, another spiritual purifier. The perforators and incense were carefully arranged inside the bundle, along with feathers and jade beads.
To López Luján's surprise, several feet underneath this bundle lay a second offering, this one in a stone box. It held the skeletons of two golden eagles—symbols of the sun—with their bodies facing westward. Surrounding the eagles were 27 sacrificial knives, 24 of them dressed up in fur and other costumes, like raggedy puppets, to represent deities associated with the setting sun. By last January, the team had uncovered a total of six offerings in the shaft—the last one 24 feet below street level and containing a ceramic jar filled with 310 greenstone beads, earplugs, and figurines. The placement of every excavated object appeared to be governed by an exquisite logic, re-creating the Aztec Empire's entire cosmology.
It was at the very bottom of the second offering box that López Luján encountered the elaborately ornamented animal. Covering it were seashells and the remains of clams, crabs, and snails—creatures brought to this spot from the Gulf of Mexico, and the Atlantic and Pacific Oceans. In Aztec cosmology, López Luján knew, this tableau suggested the first level of the underworld, with the canine serving to guide its master's soul across a dangerous river.
But which human soul? Since the Spaniard Hernán Cortés's conquest of Mexico in 1521, no Aztec emperor's remains have been discovered. Yet historical records say that three Aztec rulers were cremated and their ashes buried at the foot of the Templo Mayor. When the Tlaltecuhtli monolith was found, López Luján noticed that the god depicted held a rabbit, with ten dots above it, in its clawed right foot. In the Aztec writing system, 10-Rabbit is 1502—the year, according to the codices surviving from the era, that the empire's most feared ruler, Ahuitzotl (pronounced ah-WEE-tzohtl), was laid to rest amid great ceremony.
López Luján is convinced that Ahuitzotl's burial place is somewhere near where the monolith was found. If he is right, then the Aristo-Canine may be a subterranean guide into the mystique of a people we know as the Aztec, but who called themselves Mexica (pronounced meh-SHEE-ka), and whose legacy forms the core of the Mexican identity. If López Luján finds Ahuitzotl's tomb, it will be the culmination of a remarkable 32-year inquiry into one of the most mythologized and misunderstood empires in the Western Hemisphere. Alas, little is certain when it comes to the Aztec Empire—a reign simultaneously brutal and complex, brief and literally paved over, yet manifestly prominent in a nation's consciousness a half millennium later.