The Exterminating Angel (1962, Mex.) (aka El Angel Exterminador)

In Luis Bunuel's surrealistic fantasy-black comedy about the degeneration of human nature [Note: In Woody Allen's Midnight in Paris (2011), the Owen Wilson character, screenwriter Gil Pender, sent back to the 1920s, suggested the idea for this film to Luis Bunuel]:

• the sequence of a bourgeois hosted dinner scene - after attending a religious operatic play about a naive virgin ("Virgin Bride of Lammermoor"), twenty members of the vain, privileged class became dinner guests at the opulent Mexico City estate on the street of "Calle de la Providencia", hosted by aristocrat Senor Edmundo Nobilé (Enrique Rambal) and his wife Lucia (Lucy Gallardo); (note that the guests arrived twice in quick succession); after the meal was no longer attended by proletariat workers (another repetition: the cook and other servants had left - pictured from two different camera angles), the steward Julio (Claudio Brook) was left to serve, while Edmundo offered two toasts; afterwards, the guests retired to the music room, and appeared to settle in for the night
• the unusual circumstance that by the next morning, the guests were still there, having given up on all decorum and lounging on chairs, couches, and on the floor ("We turned this room into a gypsy campground"); a lecherous elderly composer snuck around in the middle of the night kissing sleeping women
• curiously, they had hesitated to leave even though the door was wide open - they were either trapped or held in for days by an inexplicable and baffling force, a psychological barrier, a lack of will, overwhelming lethargy, sheep-like behavior, or by rueful acceptance or suggestion; the same kind of barrier prevented outsiders from entering
• the guests' degeneration into animal-like behavior (with quarreling, hysteria, and aggression); they became ravenously hungry, slaughtered lambs that had wandered into the room, broke through the brick walls to access drinking water in the pipes, and burned the furniture; the stench of the bodies of two engaged lovers Beatriz (Ofelia Montesco) and Eduardo (Xavier Massé) who had suicidally killed themselves (by slitting their wrists) came from their hidden location in a closet; eventually the desperate party guests barbarically turned against their aristocrat host for feeling self-entrapped and insulated
• in the film's mirroring twist ending, when they finally exited the house, the guests entered a cathedral to attend a funeral mass; again, they became confined as parishioners inside a Catholic church (the clergy were trapped also) after the morning service; there was a riot in the streets, and the military was summoned to gun down the rioters
• the film's last image - a herd of sheep wandered toward the church and entered in single file, as the church bell tolled