Más Negro que la Noche

• The film premiered in Mexico on December 25, 1975 — a Christmas Day horror release, written and directed by Carlos Enrique Taboada.
• It belongs to Taboada's loose gothic cycle alongside Hasta el viento tiene miedo (1967), El libro de piedra (1968), and Veneno para las hadas (1984) — the run widely credited as the first modern Mexican horror films and a direct influence on Guillermo del Toro, whose The Devil's Backbone and Pan's Labyrinth pay tribute to him.
• The dead aunt's black cat is named Bécquer, after Spanish Romantic poet Gustavo Adolfo Bécquer — a literary in-joke threaded into a story about the dead refusing to stay quiet.
• The cast stacked Mexican stars: Claudia Islas as Ofelia, Susana Dosamantes as Aurora, Lucía Méndez as Marta, and Helena Rojo as Pilar, plus Pedro Armendáriz Jr.
• It was shot in a real manor at Hidalgo No. 95 in the Del Carmen neighborhood of Coyoacán, Mexico City — the building now operates as a school.
• Vinegar Syndrome restored the film in 4K from its original 35mm camera negative and released it to English-speaking audiences as Blacker Than the Night, in the Blu-ray collection Mexican Gothic: The Films of Carlos Enrique Taboada.

The murders aren't random hauntings — they're proportional sentencing. Each woman dies in a manner that mirrors her role in the cat's neglect and the cruelty of the household, making Tía Susana less a vengeful ghost than a judge handing down matched punishments from beyond the grave.

The black cat is a stand-in for the aunt herself. Bécquer dies almost immediately after Susana, and the apparitions intensify only once the animal is gone — read that way, killing the cat is the real murder, and everything after is the aunt's soul, denied its last earthly tether, clawing its way back into the house.

The mansion functions as a closed moral system: the inheritance is a contract, the women break it, and the house simply enforces the terms. The horror isn't supernatural intrusion from outside but the property's refusal to let anyone profit from breaking a dead woman's one condition.

Four young women inherit a crumbling Coyoacán mansion from a dead aunt, with one string attached: keep her black cat alive. They don't. When the animal turns up dead, the spirit of Tía Susana starts collecting on the debt. One woman is found hanging, another goes off the stairs after meeting a ghost in the dark, and the bloodiest reckoning waits at the end of a pair of knitting needles. Taboada turns a petty act of neglect into a slow, patient haunting where the punishment always fits the carelessness.