This article is part of our One Perfect Archive project, a series of deep dives that explore the filmmaking craft behind some of our favorite shots. In this installment, we look at how Denis Villeneuve’s Sicario shines an unbiased lens on the Drug War.

War stories are usually tales of heroism, chronicling the events of brave soldiers who fight in the pursuit of a noble cause — whether that’s toppling tyrants, thwarting invasions, or protecting normal people from dangerous regimes. It goes without saying that war is ugly, but sometimes it’s necessary, and usually, there’s at least one side with a justifiable reason for killing.

The battle between good and evil is a common theme in war stories. There are heroes and villains, and the former tend to abide by an ethical code. But war is more complex than such a simplistic notion, and sometimes the cost of victory comes at the expense of what’s morally redeemable.

Denis Villeneuve‘s Sicario uses the War on Drugs as a backdrop to pose such questions about morality. The story is a common one: a cop (Emily Blunt) accepts an assignment to take down a cartel’s drug empire, only to realize that her fellow agents don’t play by the rules of the book. But maybe they’re justified in their actions.

The team, which includes Kate (Blunt), Matt (Josh Brolin), and Alejandro (Benicio del Toro), is sent back and forth between the United States and Mexico border on an illegal, covert mission. Protocol and due process do not apply here, and questionable acts are committed by the agents to complete the mission at hand.

Unlike many other action-thrillers that feature clear-cut heroes and bad guys, Sicario takes a more nuanced approach to proceedings, operating in a moral grey zone that’s as thought-provoking as it is terrifying. In this world, the cops are arguably just as corrupt as the drug peddlers, even though they seemingly commit atrocities for a noble cause.

When we meet Kate, she’s an honest cop who believes in doing things the right way, even though seeing the horrible effects of the drug war makes her question her own set of ideals at times. For example, early on, she discovers a house she knows belongs to the cartel that is filled with bodies. With no way to legally prove it, though, she must bite her tongue.

Throughout the film, however, her views change when she loses faith in the justice system after realizing that the shadier actions of her colleagues are more effective than following protocol. Despite her persistent protests, she secretly knows that dirty tactics yield results.

“Nothing will make sense to your American ears, and you will doubt everything that we do, but in the end, you will understand,” says Alejandro, briefing Kate before the mission.

In the excellent video essay “Sicario: The Mirage of a Moral World,” Youtuber Digging Deeper notes that the concept of morality versus immorality is highlighted through the film’s use of color. Characters who wear blue are moralistic, those who wear black are corrupt, while those who are clad in beige occupy a complex grey area.

Kate’s gradual moral degradation manifests through color as well. In the beginning, when she’s still doing things by the book, she wears brighter blue colors. As the movie progresses, however, her attire becomes darker and more desaturated. This is symbolic of her journey from optimistic rookie cop to jaded, cynical operative. By the end of the film, she’s willingly compromised her morals, but she understands the necessity of their shadowy actions, just like Alejandro said she would.

That said, while the film explores these disturbing moral quandaries and portrays them in an honest, ugly light, at times the agents’ actions feel justified. They’re thrust into a hellscape, and the people they’re up against are responsible for crimes that are much worse than theirs. Sicario challenges us as viewers to confront our own moral compass and make up our own mind about what’s right and wrong. Do the ends justify the means if it’s a victory — no matter how small — in the War on Drugs? That’s up to you to decide.

Of course, no matter how justified their cause may seem, it’s hard to root for the agents. This is especially evident during the scene where Alejandro, fueled by a personal vendetta against a drug kingpin who killed his wife and daughter, shoots his foe’s children while they’re eating dinner. He gains nothing from it beyond personal satisfaction, but his actions won’t fix anything. In this world, violence begets more violence, and innocent people suffer as a result while the vicious cycle continues.

In Sicario, the line that separates good and evil is meaningless. As the history of war has proven time and time again, though, sometimes the only way to combat the bigger threat is to get your hands dirty. However, when you cross that immoral line, it’s impossible to come back.