At the beginning of "No One Gets Out Alive," we see some "archival footage" of what appears to be a stone box being excavated from ancient ruins in Mexico in the '60s. Throughout the rest of the film, the box continues to reappear in Ambar's dreams, and we finally get some answers about halfway through. While Ambar rifles through one of the rooms in Schofield Heights, she finds the family heirlooms of the property manager Red (Marc Menchaca), whose father was the archeologist shown in the archival footage from the film's prologue.
A quick glimpse of some of the documents Ambar finds shows a scene almost exactly like what we see at the end of the film: a drawing labeled "Itzpapalotl in Tamoanchan" featuring a stone box with a decapitated body underneath. The final reveal in "No One Gets Out Alive" shows that the creature living inside the mysterious box is an ancient entity. Red and his brother sacrifice young immigrant women to this being in exchange for blessings after they'd discovered their father did the same thing. The creature is modeled after the real Aztec religious figure Itzpapalotl, and it is depicted as a sort of moth/woman monster.
According to Aztec mythology, Itzpapalotl is a skeletal warrior who watches over the heavenly land of Tamoanchan. She's often depicted with jaguar claws and wings adorned with obsidian knives, and her name translates to both "obsidian butterfly" and "clawed butterfly," per Aztec Calendar.
