Julian Noble (Pierce Brosnan) is very good at what he does. The best, actually, his employer absolutely in love with both the skill and the precision he uses to deal with all of their business problems. But Julian is taking no solace in being the best. Stuck in Mexico City, waiting diligently for his next assignment, the good-looking Brit is a sweaty, chain-smoking mess. You see, Julian’s business is murder, and after decades of doing whatever he’s asked the murder business is finally killing him.

Entering this mid-life crisis is Danny Wright (Greg Kinnear), an American also in Mexico City hoping to close a major business deal with the local government. Danny’s in a rut, needing this south of the border opportunity very badly. While life with wife Bean (Hope Davis) is good, the two finally recovering from a tragedy that almost sunk their marriage, financially things could be a lot better. This deal will solve all of their problems, getting the couple out of debt and paving the way for Danny to reignite a stalled career.

Over late-night margaritas the hit man and the entrepreneur strike up a conversation that awkwardly evolves into the most unlikely of friendships. Soon these two are sharing secrets, both learning from the other the intricacies of their chosen professions and intimate details about their personal lives. In-between beer, chips, salsa and a lot more margaritas, the two discover that they’re laying themselves bare to the other, admitting things they wouldn’t even tell a priest let alone a stranger. But when work intrudes for both Julian and Danny, and when assistance is required by one to help the other finish a few things off, this newfound friendship, so tight and close and bordering on perfect, might not make it out of Mexico intact.

Writer-director Richard Shepard couldn’t have asked for anything as good this Christmas as getting Pierce Brosnan to star in his minor hit man comedy-thriller “The Matador.” If anything, Santa probably skipped his stocking completely, realizing Shepard got the best gift possible right after the one-time James Bond said his first lines into the camera. No bones about it, Brosnan is that good and more as the aging philandering drunken playboy assassin, shattering his iconic image so completely and with such self-effacing glee I can’t imagine another fitting the role so perfectly. It is an electric performance, breathlessly funny and surprisingly introspective laced with arsenic-lined emotionalism. In fact, I’d go so far as to say Brosnan does far more for the movie than the movie does for him, Shepard completely unable to craft a tale to match his star’s magnificence.

Not to say that “The Matador” disappoints. Not at all. If anything, this surreal buddy flick is as sharp and as witty as they come. While there are some colossally unfortunate missteps in the final act, getting there is such a laugh-out-loud joy I really don’t care if Shepard can’t quite bring it all together. For the most part, the filmmaker’s writing is hip, character-driven, hilarious and filled with unexpected heart. The film goes places little noir thrillers normally don’t have the nerve to go, getting there with so much style and outright hilarity a person could almost turn a blind eye when things finally do go off the rails.

Almost. The last twenty minutes play so fast and loose you almost get the feeling Brosnan and Kinnear are making it up as they go along. Plot holes I wasn’t really noticing before suddenly start looking the size of whales, while the once consistent tone starts shifting so haphazardly it is impossible not to notice. Worse, much of what does finally occur is forced and far too silly, and an awkward late-night revelation is much too sudden and unearned to achieve the emotional response I’m sure Shepard was shooting for.

Good thing the rest of it plays like gangbusters. Davis looks like she’s having the time of her life, and when she finally shimmies up the nerve to ask to see Julian’s gun I couldn’t help but laugh out loud. Kinnear is even better, sharing pitch-perfect chemistry with his costars that is as believable as it is intoxicating. Their lives may be complete opposites, but Danny and Julian share a connection neither one of them truly understands. Kinnear makes these feelings tangible, beautifully walking a very think line hovering somewhere between truth, friendship, fear and blind panic. It’s sublime work, every bit as good as his Oscar-nominated turn in “As Good as it Gets,” and it is a pity this minor movie won’t be seen by enough people to get him a second nomination.

Start to finish, though, “The Matador” is Brosnan’s bullfight and he’s mesmerizing. Julian is a homoerotic enigma, a pansexual blank slate of a human being trapped behind sarcastically impersonal walls of his own design. If Shepard ultimately doesn’t know where his film is going, his star certainly understands what the future holds for his main character. Going from high to low, from happiness to sorrow, Julian’s business is death, and with Brosnan giving the performance of his career business isn’t just booming, it’s murder.