Johnny Depp’s career has been in a slump the last few years, with bombs such as the bloated “The Lone Ranger,“ the unnecessarily baffling

“Transcendence,” and let’s try to forget the abysmally unfunny mess known as “Mortedcai.”

Now, it seems Depp has finally rebounded and taken on his grittiest role by far to date in “Black Mass.”

The movie tells the true story of James “Whitey” Bulger, a small-time gangster in South Boston who had control of all organized crime in that area. Bulger’s brother is Billy Bulger (Benedict Cumberbatch), a senator from Boston. The FBI, headed up by agent John Connolly (Joel Edgerton), comes to Bulger with an offer he can’t refuse. He wants Bulger to become a rat and go after the Angiulo brothers of North Boston, a vicious criminal organization that has connections with the mob.

They want Bulger to give them all the intel necessary in order to arrest them and, in return, the FBI will turn a blind eye to Bulger’s own criminal activities.
Bulger supplies them with the information they need, but he’s still determined to do things his way. Even after he’s outlived his usefulness,

Connolly still forms an alliance with Bulger while remaining loyal to him and the FBI simultaneously.

The movie is gritty and authentic throughout. Depp gives us his best film and performance in years. He creates a characterization of Bulger that is at once thrilling, riveting, chilling, mesmerizing and terrifying. No doubt he will receive an Oscar nomination for best actor; I will consider it an enormous upset if he doesn’t.

The rest of the picture doesn’t really work as well, however. When Depp is on screen, he commands it every second. When the film’s focus is on other characters, the movie loses a bit of its gravity.

This is a film with an epic subject matter, yet the filmmakers seem to have gotten lost in the mechanics of straightforward crime procedural material rather than taking it to its potential.

I think the filmmakers had higher ambitions, but lost sight of them along the way. It often plays like an episode of “Law & Order” instead.

That isn’t to say that the rest of the cast is bad. They give solid, effective performances, but too much of the time, they play their roles a little too straight and conventional for my taste.

Boston is certainly an intriguing locale for crime dramas. Just go back to Clint Eastwood’s “Mystic River,” Martin Scorsese’s “The Departed” or

Ben Affleck’s “The Town.” Those films explore all of Boston from very different angles and do it to much more tremendous effect than this did.

Despite its flaws — and it does have them — “Black Mass” largely rises on Depp’s shoulders. His performance is illuminated by one moment of brilliance after another, and that alone is enough to recommend it.

Grade: A-

(Rated R for brutal violence, language throughout, some sexual references and brief drug use.)

Hall is a syndicated columnist in South Georgia.