With his first two films, Hunger and Shame, British director Steve McQueen showed a masterful command of style and an ambition to tackle important topics. His third movie, 12 Years a Slave, takes on the institution of American slavery, a subject that comes so loaded with potential blowback that few artists ever attempt to deal with it head-on. He succeeds so strongly that the film's power is only mitigated, and not undone, by a third act that fails as storytelling even though it's likely historically accurate. The uniformly excellent cast is headed by Chiwetel Ejiofor as Solomon Northup, a free black man in 1840s America. He makes his living as a fiddle player, while his wife is a teacher. However, he is soon shanghaied by a pair of nefarious white men and finds himself on a ship headed to New Orleans; he is informed that he will now be called Platt, and is sold into slavery by an unscrupulous businessman (Paul Giamatti, more frightening than you ever expected he could be). As he toils away for the kindhearted but conflicted plantation owner Mr. Ford (Benedict Cumberbatch), who recognizes that Solomon is both educated and an artist, he butts heads with Ford's underlings, especially the casually cruel Tibeats (Paul Dano). After they have a violent altercation, Ford fears for his slave's life and sells him to Mr. Epps (Michael Fassbender), an alcoholic sadist who owns a cotton plantation. Though Epps reads the Bible to his property (as he frequently calls his slaves), he himself is not immune to the sins of the flesh. He has taken the young Patsey (Lupita Nyong'o) -- his best cotton picker -- as his lover, and this doesn't sit well at all with his severe wife (Sarah Paulson), whose jealousy and hatred for blacks fuel her many degrading punishments toward her husband's paramour. Meanwhile, Solomon bides his time, attempts to preserve a modicum of self-respect, and waits for the chance to reclaim his rightful name and his family. From a sheer storytelling standpoint, 12 Years a Slave pulls off something nearly impossible. Screenwriter John Ridley was given a lead character who has no control over his own life -- unable to flee or fight back in any meaningful way, Solomon does little more than suffer and try to persevere. That kind of character is the death of drama, but Ridley has plotted the movie ingeniously so that each scene follows logically from the actions of the previous one. This is not a random collection of horrific incidents that happened to one man; it's a harrowing explanation of exactly how and why these atrocities occurred. McQueen's grand ambitions are revealed in his overall theme, which is to show how Solomon is far from the only victim of this inhumane institution. He efficiently and effectively details how every single person who comes in contact with slavery is corrupted by its vileness. What the slaveholders do to maintain their power alters them for the worse in very real ways -- that shines through in the characters of Epps and Ford. Additionally, the victims of slavery do terrible things to survive that will leave them scarred forever. That point is driven home in the movie's best-written scene: a conversation between Solomon, Patsey, and Mistress Shaw (Alfre Woodard), an older black woman who enjoys formal afternoon tea and has servants who wait on her, all because the master of the house practically treats her as a wife. Shaw delivers a monologue full of anger and self-defensive justification for her own actions, but never drops the veil of civility. It's a showstopping scene that doesn't stand out by being better than the rest of the film, but because it's the most artistically powerful evocation of McQueen's overarching point. The other aspect that helps elevate 12 Years a Slave is that, while tackling such an important topic, it never feels self-important. The director doesn't think he's teaching you anything you don't know, and he feels no need to pass judgment or to reassure you that all of this is awful because he trusts that you're already well aware. There isn't any condescension in the movie -- just a desire to tell this one story, and in so doing expose how such a malevolent system eroded everyone who was a part of it. By presenting that theme with such purpose and clarity, McQueen allows his viewers to consider how the echoes of that time reverberate to the modern day. Also, while the film doesn't flinch from the disturbing violence that was commonplace in that era, it never wallows in the degradation. We are witness to nightmarish brutality, but it's presented in a way that makes it clear that McQueen trusts you are already horrified and don't need to have your buttons pressed. The only thing undercutting the movie is a third act that is a total dramatic cheat. The climactic confrontation between Epps, his wife, Patsey, and Solomon feels redundant by the time it finally occurs. The choices Solomon makes in that scene should destroy us emotionally, but McQueen has so assuredly expressed his point-of-view that there's an inevitability to this conflict, no matter how well-acted and artfully staged it is. Additionally, the story's deus ex machina resolution adds to the sense that the movie runs just a little too long, even if it's never dull. Like Spielberg's Schindler's List or Polanski's The Pianist, 12 Years a Slave is admirable, important, and serious filmmaking that is antithetical to what most people think of as entertainment. While it might not be perfect, it demands and deserves your attention.