Andrzej Zulawski's Diabel (The Devil) is a messy, baroque, jagged film, all sloppily chopped up and ragged, dripping in blood and grime. It is unrepentantly, unceasingly ugly and vile, wallowing in the filth and degradation of a world in which morality and ideals mean little, and in which everyone seems either half-mad or already fallen into the abyss of insanity. The film opens with its chaos already in progress, at a convent that is being stormed by soldiers. Everywhere, women are screaming, fires rage, gunshots ring out, and the whole place seems more like a mental asylum than a home for nuns. Zulawski is thrusting the audience into the middle of things, signaling that this will be a film of madness and horror, and this bracing introduction is stunning and effective, even if eventually the unrelenting hysterics and shrill pitch of the film will become more tiring and numbing than harrowing. Into this chaos wanders a mysterious man in a long black cloak (Wojciech Pszoniak), who kidnaps a nun (Monika Niemczyk) and breaks a political prisoner named Jakub (Leszek Teleszynski) out of a holding cell in the convent. Jakub had been arrested as a conspirator in a plot against the monarchy of Poland, a leader in an apparently failed revolution, but now the mysterious stranger urges him away from the convent, back towards his home, accompanied by the nun.

When Jakub arrives home, however, he finds only madness and devastation. His sister is insane and is apparently betrothed to their half-brother Ezechiel (Michal Grudzinski). His father is dead, having committed suicide in disgrace and insanity; Jakub is told that in the old man's final months, he'd mistaken his daughter for his wife and raped her many times. Jakub also finds that his mother (Iga Mayr), who'd long ago abandoned her family, was living nearby as the madam of a brothel. The final injustice is the realization that Jakub's fiancée (Malgorzata Braunek), believing him to be dead after his arrest, had married his former best friend, one of his fellow conspirators in the revolution. Everyone in the film seems to be mad or half-mad, possessed by horrible spirits. The film is shrill and loud, with a hectoring, hysterical tone. The performances are pitched in only one key: everyone is constantly screaming and crying, tearing at their clothes, falling to the floor and thrashing around, shivering and shaking, laughing like lunatics. It's as though the whole world was an insane asylum — or as though Zulawski had assembled a cast of epileptics to act through seizures and convulsions. What's compelling for fifteen or twenty minutes quickly becomes exhausting; everyone Jakub meets acts in the same dazed, distant manner, then falls to the floor and thrashes around while screaming.

Although it's obvious that Zulawski is trying to create a portrait of a world gone mad, seen through the eyes of a man who finds only degradation and horror everywhere he goes, the uniformity of the film's tone and the repetitiveness of its incidents quickly become boring. Zulawski can only eke so much shock value out of his bloody, horrible scenarios, as the stranger leads Jakub on a guided tour of the wasteland that has become his life. The man urges Jakub to wallow in this devastation, and to react to it with murder, using a razor provided by the man at key moments. It is obvious, from the film's title, that the stranger is a metaphorical devil perched on Jakub's shoulder, always showing up whenever Jakub needs a little push to commit the next atrocity, always providing another little nudge towards evil and sin. The stranger wears Jakub down until he is totally weak and defeated, unable to resist any act — and it is only then, in one of the film's cleverest conceits, that the stranger reveals the very base, very human motivations behind all this horror and ugliness.

This very human devil is, in fact, the most interesting aspect of the film. He is a sniveling, cowardly figure, not at all intimidating or frightening. He is jittery and nervous, like the low-level clerk he's referred to as at one point. He is a servant rather than a leader, an anxious fly buzzing obsessively around Jakub's head, whispering in his ear, planting seeds of ideas and letting them sprout into actions. Zulawski cleverly does not give this "devil" too much power, does not make him imposing. He is a base, pathetic creature, a parasite who feeds on the weaknesses of others — and he finds plenty of weakness to satiate him. Towards the end of the film, the aimless Jakub asks if the world is really so ugly as he believes it to be, or if it's actually beautiful. The stranger praises the world's beauty in ineffectual terms, then purports to demonstrate its beauty through dance — but his dance is as spastic and chaotic as everything else in the film, a lame testament for the world's beauty from an ugly, pathetic man. The film puts little stock into art in general: Jakub comes across a troupe of performers and actors, but they are predatory and aggressive, with the troupe's gay leader trying to rape Jakub. The troupe's performance of scenes from Hamlet only mirrors back to Jakub the themes of betrayal and familial dysfunction that he finds everywhere he turns in his own life. Later, he says he finds comfort in the arms of the woman who plays Hamlet's mother in the play, but this is a short-lived pleasure that ends in more violence, and in any event it can only be linked to Jakub's own incestuous "punishment" of his own mother.

There is, doubtless, an allegory hidden within this film somewhere, if one could dig through its layers of blood and dirt. It is a film about the corruption of humanity, about how an idealistic young man who wishes to fight for his dreams is instead twisted into an instrument of violence and terror, serving interests contrary to his stated ideals. Zulawski apparently intended the film as a response to a very specific incident involving student riots in Communist Poland, but it can just as easily be taken as a general statement on the destruction of ideals through temptation and exploitation.

That is, if one can get past the film's exhausting hysterics. Zulawski conveys the disconnection and dazed state of Jakub effectively through his fragmentary editing, through which the young man often seems to be leaping spasmodically from location to location: one moment he might be in a springtime forest, the next passed out on a snowy hill. This disjunctive editing is effective at adding to the film's destabilizing feeling, and also lends a supernatural aura to the film's "devil," who often seems to appear out of nowhere, always in the right place. The editing winds up being one of the film's most compelling elements, however. Diabel as a whole is simply too shrill, too repetitive, too silly in its theatrical overacting and constant fits of contrived "madness." It opens in insanity and maintains the same fevered pitch throughout, which over time dulls whatever effect Zulawski was going for. Diabel is sporadically interesting, often visually provocative, but ultimately inconsequential.