A man sharpens his straight razor on a strap, and goes outside to stare at the Moon, which has thin clouds passing in front of it in the night sky. This inspires him, and he returns inside, takes his blade and slices open a woman's eyeball. Meanwhile, a man (Pierre Batcheff) is cycling through the city streets on the way to the apartment of his sweetheart (Simone Mareuil) when he starts to suffer, and once he reaches his destination he has dropped to the ground in exhaustion. She sees this and rushes down to attend to him, showering his face with kisses. It's almost as if none of this makes any sense at all...
Un Chien Andalou was the collaboration between two of the leading Surrealists, director Luis Buñuel and his co-writer Salvador Dali; the former would pursue his interest in film, while the latter would, after parting ways with him, become an artist in paint and what could best be described as sculpture, eventually turning his whole life into a statement on the movement. Dali would occasionally return to the moving image, but Buñuel used his interests towards subversion, often crafting films that were deeply indebted to what he created with his former collaborator here.
As to a plot, there wasn't one, it merely consisted of a succession of images designed to evoke the dream state through a selection of the two men's own dreams and the odd satirical barb and deliberately provocative shot, such as the eye damage in the first minute that retains its power to shock even now. It was a dead calf's eye that was slit, but that doesn't make it any the more palatable since the editing makes it clear we are supposed to be thinking of the woman's eye when we see it happen. But if you think the horrors were over with that, you had another think coming.
This was, considering it lasts a mere twenty minutes, incredibly influential in all sorts of ways, and has been referenced by, or inspired, many other works. The Pixies opener from their classic album Doolittle features lyrics discussing the short, Saul Bass's cult science fiction film Phase IV replicates the visual of ants crawling from a hole in a hand, and in blockbuster The Matrix, Keanu Reeves sees himself with no mouth, much as a character does here. With that in mind, you might believe it to be a fun watch, a wacky little item from cinema's early days before sound became the norm.
However, the mood may be playful in some ways, as when the man drags two grand pianos containing dead, oozing donkeys across the room and we notice he is also pulling two priests across the floor as well, but for the most part it was clear the artists wished to disturb, to disrupt. If you were actually having a dream like this, you would be doubtless prompted to sit up bolt upright in bed staring straight ahead in time-honoured "waking up from a nightmare in a movie" fashion, as while there was a plethora of arresting images, the overall impression was one of complete, ruthless chaos.
It's not as if they were denying there were any rules - don't attack people, don't grope women who don't want to be groped, don't stand in the street or you'll be run over, and so on - it is more they had concluded all rules did not matter, and that can make the film haunt your thoughts in ways that you may not enjoy. Add to that the two stars committed suicide eventually, Batcheff with an overdose and Mareuil by setting herself on fire (!), and Un Chien Andalou looks less like a jape and more like a cruel joke at the expense of humanity. But you cannot deny it succeeds completely; if you did suffer this nightmare, it would be stuck in your brain for years, aggressively reminding you of the unruly subconscious.