On a rainy Thursday night two weeks ago, I made my way to the Bryant Park Hotel, a swanky boutique place in midtown Manhattan, and watched an episode of Law & Order: SVU. Not in a suite or anything, but in the hotel's downstairs screening room. I was met by publicists from NBC and told to order something from the bar — a glass, OK two glasses, of pinot noir, in nice stemware! — and shook hands with SVU's current showrunner, Warren Leight. The screening room wasn't terribly big, so pretty soon I was sitting not far from a few of the show's stars: Richard Belzer, Danny Pino, and, commanding focus in a formfitting red dress, Mariska Hargitay. Leight gave a little speech before the episode, which played to gasps and applause, and then there was a cocktail reception where people mingled with Mariska.

It was an undeniably peculiar way to watch a show that, I think, most of us usually watch in our pajamas on the couch in some sort of Sunday afternoon rerun marathon. SVU, which is the last of the once-mighty Law & Order franchise, has been on since 1999; a whopping 319 episodes have already aired, likely to still be playing in syndication long after all of us are gone. The episode I saw in the screening room was the 320th, the premiere episode of show's fifteenth season. So why all the pomp and circumstance — well, free drinks at least — for this old dog? What's everyone so excited about? Well, as the intense, spare, and even artful episode showed, SVU has learned some new tricks of late, becoming one of the best dramas on network television in the process. It's a shift I'd noticed even before the free wine. (Honest, check my Twitter!)

The change started with the thirteenth season, when Leight, a Tony Award-winning playwright (Side Man) turned TV writer, was brought in to steer the ship in its new post-Chris Meloni era. Meloni, who played one half of the show's central will they/won't they pair of sex crime detectives (they didn't, in the end), left the show rather abruptly and took with him what had become, in some ways, the show's main dramatic engine. Fans were beside themselves, but instead of throwing in the towel, NBC chair Bob Greenblatt saw an opportunity for change. So he asked Leight to tweak the series, a daunting proposition, but one Leight told me he seized with relish.

"I think everyone thought, 'Well Warren's just been put on the Titanic,'" he said in a phone conversation this week. "But it became the luckiest break imaginable in a way." Throughout our chat, Leight was careful not to criticize the SVU that came before him — "it was working very well" he stressed several times — but when asked what he thought needed changing, he said, "I wanted to change the way the stories were told, so that they were a little less... I guess melodramatic. I wanted a little more naturalism." He explained that he "wanted to get back to the original conceit, which was that the victims were in fact alive. It had become much more of a raped-and-murdered show. And in real life those cases are handled by homicide detectives." Leight said he was interested in "what that experience was like, of a victim going through the system."

He also took the show outside more. "There was a lot of medical on the show. There was a full set that was set up full-time as a hospital and we turned that back into a swing set. I wanted to use the city a lot more. It's easier to put everything on a stage, you can control it more, but I wanted the city as a real character in the show. And I think we went back to more ripping from headlines than had been the case." That last bit might immediately conjure up something cheesy or sensationalistic, but Leight's approach is more restrained. "We have one coming up and it just sounds so cheesy," he said of a future episode starring Cybill Shepherd as a Paula Deen-esque character. "The 'celebrity restaurateur who fears for her life and shoots a hooded black teenager' episode. It sounds like a cheesy mashup. I'm hoping we'll get people to watch, but when they watch they'll see that it's not at all a cheesy episode. It's a very realistic depiction of the trial and how it works."

Leight's concerns about things being realistic and decidedly not cheesy have had a noticeable, and exciting, impact on the show. What had become a series mostly known for Meloni's too-close-to-the-case bellowing and the elaborate plots' grand "twists and turns," as Leight calls them, has turned into something quieter, thoughtful, even. And there's a new attention to artistry. Leight referenced an episode two seasons ago that barely used any music. The season premiere, which airs tonight at 10 p.m., is in many ways a two-hander, between a sadistic rapist/kidnapper played by Pablo Schreiber (Orange is the New Black's "Porn Stache") and Hargitay's Det. Olivia Benson. Hargitay does a lot more capital-A Acting in the episode than we're used to seeing from her, but it doesn't play like shameless Emmy reeling or, y'know, melodrama. Her brutal scenes are urgent and scarily intimate, setting the stage for a season-long character arc. That's another new thing Leight is trying, giving the season some shape rather than having every episode be perfectly standalone and syndication-ready.

Obviously this show's difficult subject matter, harrowing and grim as it all is, will never be to everyone's liking, but what Leight and his writers have done in the past two seasons has made the material palatable not by being wickedly prurient or leering, but by addressing these themes intelligently, with shading and texture. The show is actually Saying Something about these frightening and uncomfortable topics, not with the broad-strokes speechifying you may expect, but in subtle and deceptively complicated ways. Leight says of the show's tone, "SVU covers cases that are gray." That's a tricky line to walk, especially for an old network drama like this one, but they've been mostly, and perhaps miraculously, pulling it off, week in week out, for the past two seasons.

SVU hasn't exactly entered the annals of so-called prestige television, but for having such a late-in-the-game renaissance, and for doing so with smarts and simplicity instead of showy tricks or casting stunts (the guest casting of late has been especially sharp), it's a show worth giving another shot. It's a bizarre thing to say about any series, but Law & Order: SVU's fifteenth season could wind up being its best.