You need to watch the best legal thriller of the century before it leaves HBO Max next week

In lieu of Star Wars or Marvel movies, the biggest cinematic heroes of the 1990s were lawyers. Legal thrillers became massive hits, where lawyers battled through corrupt systems to find some form of justice. The trend peaked — or jumped the shark — with 1997’s The Devil’s Advocate, a movie in which Lucifer himself heads up a law firm.

The Devil’s Advocate was all bombast and screaming, an epic drama of Good vs. Evil played out in courthouses and boardrooms. When the movie’s co-writer, Tony Gilroy, did some research at actual law firms, he told Filmmaker Magazine that he was “really struck by how unrepresented an actual law firm was on film… when you go to a law firm to shoot location at 3 o’clock in the morning, it’s shocking: there’s three or four lights on every floor and some poor person buried under paper. It’s not pretty people and it’s not a pretty atmosphere, it’s really a grind.”

Research for the bombastic Devil’s Advocate eventually led to Gilroy’s directorial debut a decade later, Michael Clayton. It’s a legal thriller that’s different from The Devil’s Advocate in every possible way. Michael Clayton is a slow-burning movie with no black and whites, just a world of gray where even the sharks are drowning.

Clayton (George Clooney) is a lawyer whose best days are behind him. He works at a high-powered corporate firm, but he’s not the guy calling the shots or leading the litigation. His colleagues tell clients that he’s a miracle worker, but he considers himself more of a janitor. He does clean-up for messy clients, people who make mistakes at 3 a.m. when their regular lawyers are on vacation.

He has connections all around New York, but he’s not particularly happy with his lot in life. He tried investing in a bar with his brother, but the bar failed. So he gambles away his life in backroom poker games. He doesn’t have much purpose until one of the firm’s top lawyers, Arthur Edens (Tom Wilkinson), has a complete mental breakdown in the middle of a deposition.

Michael Clayton starts with a car exploding in the middle of a rural road, as Michael admires a few horses. It then backtracks four days previous to see what happened. For the last six years, Michael and Arthur's firm has been handling the case of United Northfield, rebranded as U-North, an agribusiness company accused of making a lethal fertilizer.

Arthur, who has a history of mental instability, has a sudden crisis of conscience and strips down naked in the workplace. He’s stopped taking his medication and has taken to rambling about losing all purpose in life. The U-North case, particularly one lawsuit concerning a girl named Anna (Merritt Weaver), has become all-consuming for him.

Michael is sent in to swab up Arthur’s mess. Along the way, he tangles with U-North chief legal counsel Karen (Tilda Swinton), who is furious at the firm’s breakdown. As Michael starts to sift through the lies and the truths behind Arthur’s sudden shifts, he finds himself in over his head.

Michael Clayton is a movie that requires careful attention. Its plot gets tangled in legalese that can become confusing if you’re looking at your phone for a couple of minutes. Why is Michael’s boss Marty (the legendary director Sydney Pollack, whose work influenced much of this movie’s style) mad at him again? What is he trying to gain? On its most basic level, Michael Clayton is mostly people in rooms talking to each other.

But Michael Clayton deeply rewards the viewer willing to spend time with it. Gilroy’s first movie couldn’t be farther from The Devil’s Advocate in its muted colors and characters with incredibly average and depressing lives. The movie refuses to find a moral center, letting Clooney and Wilkinson’s terrific performances carry the day.

The weight of Clayton’s world is laid bare on Clooney’s face, completely removed from the carefree life of Ocean’s Eleven. Arthur is his mirror, out of control and feeling joy for the first time in decades. This is an actor’s movie, and everyone is operating at their highest levels. Even Pollack has a scene-stealing performance.

As a movie of pure tension, an anti-legal thriller, Michael Clayton is one of the best of the century.

Michael Clayton is streaming on HBO Max until September 30.