After a dinner party, about twenty ridiculous upper-class people (and one waiter) are mysteriously unable to leave the room. And nobody outside can enter the house. They do get out, over a week (and three deaths) later, by recreating the moment when it first happened, standing in the same position they were at 3am the first night. Then they all go to church together and it happens again.
In between, we’ve got chicken feet in a woman’s purse, mountain vistas in the bathroom, dreams and voiceovers, sheep and bears running through the house, morphine, lovers dying mysteriously, and the total breakdown of high society.
Hard to keep track of who’s who most of the time, except for the gay guy who complains a lot. I occasionally recognized Silvia Pinal (the hostess, Tristana). The steward Julio is Simon of the Desert, and a few other actors from this one were in Simon (incl. Silvia as the devil). A couple of these guys were in Bunuel’s early Mexican movies, one woman was in Brainiac, and two people were in Samson vs. The Vampire Women, released the same year!
A Brazillian movie won the Golden Palm at Cannes that year, beating Exterminating Angel, Cleo from 5 to 7, L’Eclisse and The Innocents. The IMDB is probably stretching when it says this movie was referenced in both A Nightmare On Elm Street and The Blair Witch Project.