For those that think acclaimed director Martin Scorsese has been MIA since his last widely regarded masterpiece “Goodfellas” then get ready for “The Departed.” This dynamic crime masterpiece finds the filmmaker firing on all of his creative cylinders, the film a brilliantly acted tour-de-force of corruption and circumstance easily ranking as one of the year’s very best motion pictures.

Technically this is a remake of the very good 2002 Hong Kong thriller “Infernal Affairs,” but just because you’ve seen that crackerjack epic (or its sequels) don’t imagine for a moment you have the slightest idea where this one is headed. William Monahan has taken the basic thread of that one; police plant an undercover operative inside a crime lord’s crew, he does the same to the cops placing one of his own inside their detective squad; and then fashioned something completely different and altogether extraordinary.

Scorsese laps this world and its milieu up with a spoon. This is a return to the dingy avenues of “Mean Streets,” to the perverse ironical cynicism of “After Hours,” to the filial decay and depravity of “Goodfellas.” This is the director at the very top of his game, weaving a myriad of characters and their labyrinthine subplots with the skill and dexterity of a genius. “The Departed” grabs you by the throat in the very first frame and then refuses to let go finally leaving the viewer battered, bruised and, ultimately, exhilarated by the time things reach their tragically preordained conclusion.

Billy Costigan (Leonardo DiCaprio) is a rookie police officer from South Boston – a “Southie” – assigned to infiltrate an all-powerful mob run by the larger-than-life Frank Costello (Jack Nicholson). No one will know who he is and what he is doing other than his two superiors Captain Queenan (Martin Sheen) and Sergeant Dignam (Mark Wahlberg). Virtually cut off and completely on his own, Billy must impress Costello while also feeding the cops information, both without getting himself killed in the process.

Another young Southie has also found his way to the Massachusetts State Police. Colin Sullivan (Matt Damon) has proven himself a man of intelligence, talent and ambition, rising through the ranks and earning the praise and respect of Special Investigations Unit Captain Ellerby (Alec Baldwin). A good cop willing to do whatever it takes to ensnare Costello, he sees the same dogged determination in Sullivan. What he doesn’t know is that young man is secretly working against him, the mob boss sending him inside the department as an undercover mole to alert him to any and all dangers headed his way.

Soon both men are on a collision course, their double lives slowly consuming them to the point they worry the real identity hidden inside of them is going to disappear. No matter which way they turn death waits to meet them, and unless they can uncover the secret identity of the other the only real question is going to be which one of the duo is going to get the first bullet. It’s cat versus mouse with neither Costigan nor Sullivan knowing if they are predator or prey. All they do know is that it’s their life on the line, and with things falling to pieces around them that’s the one thing above all else they know they want to protect.

There are so many layers here that after a while you’re no longer sure which way is up or if down really is beneath you. Monahan throws in so many twists, turns and red herrings I kept wondering when the kitchen sink was going to show up, “The Departed” being one of the few films where you could say nothing is as it seems and not have it sound like a cliché. Scorsese juggles all of the revolving tangents with aplomb, clearly energized by both the material and the gifted group of actors bringing it all to life.

And boy are those actors something else! Damon, Wahlberg, Sheen, Baldwin and “Running Scared” siren Vera Farmiga all deliver performances impossible to take your eyes off of. Farmiga, in particular, shines brightly here, her role as a police psychiatrist who becomes associated with both Costigan and Sullivan clearly the most contrived in the entire picture. The coincidences allowing her to come into contact with these two men border on silly, the actress somehow managing to rise above the absurdity and deliver a touchingly beautiful portrayal that’s almost heartbreaking in its emotional resonance.

Yet this movie belongs to DiCaprio and Nicholson. After “Gangs of New York” and the “The Aviator,” the former finally hits his stride working with Scorsese. Third time is definitely the charm, DiCaprio delivering a crackerjack performance that’s immediate worthy of Oscar consideration. This is the best he’s been since 1993’s “What’s Eating Gilbert Grape.” Costigan wants desperately to do the right thing, descending so deep within Costello’s organization it will surely clear his family’s embattled good name. But the constant deception and the omnipresent specter of death way heavily upon the young man, DiCaprio managing to bring every rampaging thought and emotion bubbling inside the officer to viscerally devastating life.

Then there’s Jack. What else is there to say about Hollywood’s resident wild child that hasn’t already been stated too many times before? There isn’t a darn thing I could add, nothing that wouldn’t be repetitive of all that’s come before. All I can do is focus on the performance, and on that front this thirty-plus year anticipation for Nicholson and Scorsese to hook up been, without a doubt, more than worth the wait.

Costello is a rampaging dinosaur, a gregariously terrifying man who has had just about everything; every passion, every entertainment, every danger, every happiness; in his long life. He’s at the pinnacle of his power and he has been there for decades, and the only thing left for him to do is to wait for one of his underlings to grow restless and try and usurp his throne. And so he takes risks, does things (like going out on drug deals, performing his own hits and engaging in black market haggling) he probably shouldn’t. But Frank realizes his time is coming to a close, and with that being the case he’s certainly going to make sure his exit happens with a proverbial bang.

Nicholson pulls tricks out of his bag so golden they should probably be patented. There is a scene where he searches DiCaprio for a wire that is maybe as good a moment the actor has ever had. Considering this is the guy known for landmark portrayals in works as diverse as “Five Easy Pieces,” “One Flew Over the Cuckoo’s Nest,” “Chinatown,” “Batman,” “Prizzi’s Honor,” “Terms of Endearment,” “Reds” and “The Shining” that’s saying one heck of a lot. But this isn’t hyperbole. Jack is that good and more here, refusing to rest on his legendary laurels and unleashing a ferocious fireball of a performance exploding across the screen like a flaming tornado.

This is all just the tip of the iceberg. I haven’t even begun to talk about how superb the great Ray Winstone is, how fantastic Thelma Schoonmaker’s editing proves to be, how sublime Michael Ballhaus’ photography defines every cinematic detail or how Kristi Zea’s production design feels so lived-in I could imagine myself there. I haven’t mentioned how kinetically the final act comes to its spectacular coda or how unforeseen surprises pop out of the film’s corners to slap you across the face and keep you on your tiptoes.

I haven’t mentioned lots of things and that is perfectly fine. Scorsese doesn’t need me or anyone else to say how phenomenal this movie is, the proof of it is right there up on the screen for everyone to see for themselves. But I’m going to say it anyhow, try to scream it at the top of my lungs if I have to. “The Departed” is a modern day classic, pure and simple, and the only reasonable thing to do after it’s over is to run back out to the box office and buy a ticket to see it again.

Film Rating: êêê1/2  (out of 4)