There’s something noble to be found in loyalty. Your word, as they say, is your bond. What good is one’s character, if not for the strength of their personality? With regard to Whitey Bulger’s allegiance with the Boston Police Department, however — more specifically his fellowship towards FBI agent and childhood friend John Connolly — the lines of decency tend to get blurred with their trust. The unholy companionship between one of South Boston’s most notorious gangsters and one of the upholding scanties of the law shouldn’t spark overnight, though Scott Cooper’s Black Mass suggests that’s how such decades-spanning allies came to be.

One dark Boston night—with crime running rampant from the mafia throughout the city — Connolly (Joel Edgerton) reaches out to James “Whitey” Bulger (Johnny Depp), the small-time leader of the Irish-American Winter Hill Gang and his old acquaintance, on the outskirts of town with a proposition. If he feeds him information on the corruption happening around town, he'll keep him and his guys safe. Bulger’s no rat, Connolly’s told upfront, but the agent isn’t looking for a rat: he seeks an informant. Someone to put away those whom serve them each wrong, specifically the rising Angiulo brothers — criminals in Bulger’s best interest to take down. Plus, it’ll not only protect him but his family, including his wife Lindsay (Dakota Johnson) and son Douglas (Luke Ryan). It’ll also raise their social statuses in the process. When the Angiulos’ murder one of his own, Bulger finally feels compelled to take Connolly’s deal, and unshakable partners form.

Their comradery isn’t met easily with those in the know, including Bulger's right-hand man Stephen “The Riffleman” Flemmi (Rory Cochrane), fellow FBI agent John Morris (Scott Garriola) and Whitey’s brother, Boston senator Billy Bulger (Benedict Cumberbatch). It doesn’t settle well with others in Connolly’s work team either, especially as informant rules like no crime or killing are ignored, but results soon settle in and Whitey’s opposition is eliminated quickly. With little to stand in his way, the criminal's only more powerful and merciless, and Connolly’s blind loyalty prevents his federal interference. Where good intentions were once founded is lost in sight, on both ends, and the validation of one’s word gets tested further over time.

Sprawling epics are fairly commonplace in the cinema, and there’s little to distinguish Black Mass from its peers, stylistically or story-wise. Comparisons to The Departed are seemingly inevitable, and Ben Affleck’s recent directorial work fair well as influences too. Nevertheless, Cooper commands Bulger’s story with a confidence and fearlessness that’s bound to do him wonders in the future behind the camera. His resilience is astounding and confounded. Though he never strays too far from the pack, there’s something deeply chilling in Cooper’s recreation. It’s hard to shake off once it seeps in. Bulger’s legacy defined through his relentlessness, and in telling his story, the director doesn’t shy away from the violent, masochistic details creeping through. The gangster’s always a viciously lurking figure, with his shadow constantly lurking over each scene, and there's always a sense he's bound to pounce at the given opportunity.

It’s a resiliently impressionable display, provided by Depp’s captivatingly, surprisingly understated work. The darkness in Bulger’s eyes constantly thirsts for justice and validation, and the A-list star never winces at any opportunity to protrude inside the ruthlessness masked inside this real-life figure. Showy at times, as his performances constantly are, he doesn’t pull from his usual bag of tricks. Even if he’s still behind some make-up, wig and prosthetics which are constantly apparent, it’s a performance unlike any the actor’s proven he’s able to give before — signifying great promise for what he can, and hopefully will, do in the late terms of his career.

More to the point, though, Cooper and Depp constantly find the humanity woven within this deranged personality. Bulger can, at points, become fairly sympathetic, and there’s always some understanding of where he stands in his fight. You constantly know where he’s coming from, but it doesn’t hurt to have him give a monologue about the importance of trust at nearly every scene. By then, once he’s almost completely remorseless, there’s a unfortunate repetitiveness in the action, sadly dragging the entertainment factor to a near halt. Not slowing the film to a stop, but keeping Cooper from the great film he could, and should, have made — especially with Edgerton, in addition to Cumberbatch and Cochrane, providing equally compelling performances on the side. That’s not the only reason, however.

Black Mass is an easy film to compliment, from the fine ‘70s production designs to resoundingly swift pacing. It’s just not an especially praise-worthy film. It does everything it needs to well, but there’s nothing beyond its actors and fine-tuned direction separating it from what was done before. It steps in the footsteps already crossed, even if Bugler’s story wasn’t portrayed before, and isn’t far better or worse. The storytelling, initially bound between two testimonials between Flemmi and Kevin Weeks (Jesse Plemons), clumsily fades their narrations in-and-out, but because it’s all so involving it hardly makes a difference, really. It's a captivating story, and Cooper knows it and makes it worthy of its cinematic trail.

Accelerating, if rudimentary by design, there’s something to be said for how enticing Cooper makes Bulger’s life become. It hones in on something personable and honest about these uncharacteristically likable people, and that's an accomplishment on its own. There's honor to how it portrays the haunting depths of their personalities, without overstepping its boundaries and restraints. It may be loyal to the style to a fault, but it never breaks on its word. Remember, now: that’s where it really counts.