Played by Jake Gyllenhaal in a career-best performance, Louis Bloom is the definition of an antihero. He’s a thief. A hustler. A liar. A manipulator. A narcissist. A sociopath. And he fits perfectly in the world of tabloid journalism, which he stumbles into unwittingly early in the film.

All he needs to get started is a camcorder and a police scanner. All he needs to do is to drive recklessly to whatever accident or crime scene is happening in Los Angeles that night and get as close as possible to film it. The bloodier, most graphic images he can get, the better. These people are quite literally vultures, despicable bottom feeders who profit from the misery of others, something Louis has no quarrel about doing.

“I’m a very fast learner,” he tells a local news director (Rene Russo) and that, my friends, is one of the rare times when he’s not spewing bullshit. Bloom’s lack of morals allows him to repeatedly cross the line of basic human decency and to get sensational footage, for better or worse. Meanwhile, we wonder when he will finally go too far and get himself arrested or killed…

Writer Dan Gilroy, who also makes his directorial debut here, has made a gripping, unsettling, deeply cynical film. Expertly shot by cinematographer Robert Elswit, who interestingly used 35mm for the daytime scenes and digital for the nighttime ones, “Nightcrawler” is more than anything a pitch-dark character study, not unlike such masterpieces as “Taxi Driver” or “There Will Be Blood”.

Gilroy’s movie is nowhere near that brilliant, but it’s nonetheless pretty damn good, thanks in no small part to the aforementioned career-best performance by Jake Gyllenhaal. Perpetually looking like he hasn’t slept or eaten in way too long, staring intensely into the night with haunted eyes, Gyllenhaal dives right into this utterly unsympathetic role, savoring every ounce of creepiness Gilroy has poured into his screenplay.

“Nightcrawler” has some small flaws, notably a distracting score and pacing issues, but if only for Gyllenhaal’s turn as the unforgettably loathsome Louis Bloom, it’s a must-see.