“Let the feds fight our wars, against our enemies.”

So says Johnny Depp as James “Whitey” Bulger, the erstwhile boss of the notorious Irish-American crime syndicate known as the Winter Hill Gang. In its heyday, the Winter Hill Gang enjoyed something of a monopoly on organized crime in Boston, due in no small part to Whitey Bulger and his prodigious violence.

If you’ve had the pleasure of experiencing Martin Scorsese’s masterful The Departed, you have already seen a celluloid depiction of Whitey Bulger, on whom Jack Nicholson’s character, Frank Costello, is loosely based. You have furthermore seen a fictionalized depiction of Whitey’s real life FBI collaborator, John Connolly, played in that movie by Matt Damon. But while Scorsese used the Bulger narrative as a canvas onto which he could paint his own modernized conception of the Boston underworld, Black Mass, directed by Scott Cooper (Crazy Heart; Out of the Furnace) and based on Dick Lehr and Gerard O’Neill’s book of the same name, is the real story.

The film’s opening sequence consists of a series of interviews between FBI agents and Whitey Bulger’s former associates, the latter of whom have decided to turn state’s evidence. (The film’s structure implies that we’re getting the story in hindsight from those who worked closely with Bulger — as they give their testimony, we see the action.)

“I’m not a rat,” one of them declares; “I want that on the record.”

Predictably, this notion of “rats” is the overarching theme of Black Mass. Omertà, the Mafia’s famous “code of silence,” is, after all, the central doctrine of organized crime — violation is typically a capital offense, hence the necessity of federal witness protection programs.

It is interesting, then, to watch Whitey Bulger agree to what he calls an “alliance” with John Connolly (played by Joel Edgerton), a federal agent who Bulger has known since childhood. In exchange for providing the FBI information about rival gangs, Bulger is granted a degree of immunity. In other words, Bulger agrees to rat on his adversaries; the benefit of which is twofold: not only does the FBI take care of his competition for him (enabling him to expand his enterprise), but he is allowed by law to proceed with his criminal career, just so long as he doesn’t kill anyone.

As with a Ponzi scheme, the circumstances described above can be – at first, and for a while after – lucrative and rewarding. But the arrangement is unsustainable. Corruption and betrayal are inevitable, and eventually the house of cards will come crashing down. Before that happens, though, Black Mass treats us to – or rather pummels us with – a huge dose of savagery and murder, all of it either ordered, or committed by, Bulger, who has been given carte blanche by the agents he is “informing.”

The real drama arises when the venal Connolly becomes complicit in Bulger’s crimes, effectively sealing his, and everyone else’s, fate.

While the violence in this movie is indeed abundant, and at times genuinely shocking, one does not get the feeling that it is gratuitous, or even excessive. On the contrary, it is very carefully controlled, and it serves a purpose, which is to convey the extent of Bulger’s brutality (he is, after all, a real person), as well as the discomfiting reality that latent in our collective nature is the capacity to do horrific things. Furthermore, the violence never becomes tedious, as it often does in similarly themed movies.

The main takeaway here is that Whitey Bulger is a veritable monster — a mean, ugly, psychopathic killer devoid of humanity, and lacking even a single redeeming quality. Which is precisely why Johnny Depp deserves so much credit.

Channeling (but going beyond) his character in the underrated Donnie Brasco – many of the themes of which overlap with those of Black Mass – Depp takes his performance to uncommon heights. Flawless is probably the right word; certainly, it is Oscar-worthy.

To borrow a quote from the late Roger Ebert (who applied the following to Christian Bale for his role in American Psycho), Depp “is heroic in the way he allows the character to leap joyfully into despicability; there is no instinct for self-preservation here, and that is one mark of a good actor.”

Black Mass is first and foremost a document of human depravity. And in that sense, it comes up short as a work of art.

Apart from the stress induced by the procession of high impact violence, the audience is not allowed to feel anything. There is no pathos, very little humor, and no catharsis. No effort is made to understand the man at the center of all the carnage (there is only one reference to the CIA mind-control experiments Bulger underwent while serving time in Atlanta Penitentiary — something that haunted him for years).

We are entertained, surely, and there is rarely a dull moment; but Black Mass, because it contains only one dimension, ultimately fails to give the audience a complete