With its new installment “True Detective,” one of TV’s most baroque series, is keeping things simple — relatively speaking.

Some things haven’t changed: Yes, the third season restlessly jumps through time. (It moves between 1980, 1990 and 2015, to be exact.) And as Det. Wayne Hays, a cop investigating the disappearance of two children in small-town Arkansas, Mahershala Ali lends gutsy commitment and a willingness to be shrouded in old-age makeup, just as Matthew McConaughey had done in Season 1.

But what’s striking about the latest iteration of a show that’s worn its taste for excess proudly, even as the audience recoiled, is its leanness. Tightly directed (in its first episodes by Jeremy Saulnier) and plotted, and with a performance at its center that steers away from calling attention to itself, the new “True Detective” transcends hype and amounts to 2019’s first pleasant small-screen surprise.

It’s the 2010s and Ali’s Hays, a former police detective who had been partnered with a white investigator (Stephen Dorff) on a missing children case, is a source for a true-crime documentary driven relentlessly forward by a semi-scrupulous journalist (Sarah Gadon, quickly becoming one of TV’s most welcome utility players). Hays is speaking to the media to help expiate his feelings of guilt over failing to crack a case that seems just out of reach, one that resulted in a dead boy and a missing girl not recovered. But his story is complicated by the fact that his memory is slipping away from him. Ali plays the confusion of a malady not quite diagnosed, yet obvious to all but the sufferer, with grace; Hays doesn’t realize he’s in a haze and assumes that which he does not recall is unknowable — until he’s jarringly reminded otherwise.

Buoyed by Ali’s shambling confidence as a senior citizen and by crisp editing that never allows shifts in time to feel truly disorienting, the idea of a detective reinvestigating that which he cannot remember is a simple formulation. And it’s one whose elegance is all the more pronounced by contrast to what had come before. The first season of “True Detective” — the one that reinvented McConaughey’s career as a leading man and made the names of director Cary Joji Fukunaga and writer Nic Pizzolatto — was a delight and, ultimately, a frustration because of how much was stuffed into a framework that couldn’t have hoped to hold it all. The performances were rowdily massive and at times garish, battling for attention with Fukunaga’s aggressive direction; the series was suffused with literary allusions and plunges into human darkness that came to overwhelm what had been the mystery at the story’s core. A second season ditched what had worked and kept what had not — an addiction to nihilism for its own sake and a zany disregard for reason.

Little wonder that this fleeter installment feels so refreshing. Stylistic touches, like the aged Hays being visited by the ghosts of his past, are carefully chosen. And the show fits a surprising volume of ideas into its narrative, embedding well-drawn racial tensions and questions of journalistic ethics into a framework —the detective serial — that feels, finally, fully realized rather than self-indulgently pulpy.

Both of the season’s big themes come in for subtler-than-expected investigation, and from unexpected angles. Gadon’s TV hack isn’t the only reporter in the story; Hays’ schoolteacher wife, Amelia (Carmen Ejogo), ends up writing a book about the crimes, and emerges as a character that is utterly original. She’s all briskness under a surface of sweet compassion, and yet both of her sides feel real. Moved by the trauma that overtook her town, she sees absolutely no issue with profiting from it as well. She’s a creature of the say-everything media age just being born in the story’s earliest moments, and her ethical deficits rise from a wellspring of humanity — both pity for the victims and exhilaration at just how satisfying it can be to play detective.

And race, in a series whose first two seasons foregrounded white sleuths, is a persistent subtext here that challenges every character and can’t and won’t bear easy resolution. Hays and Dorff’s Roland West are easy natural allies, yet are men for whom unkind scrutiny comes readily as their story unfolds. “Is that promotion on merit, or did it come with the pigmentation?” an unbound Hays, stalled in his career and looking for someone to hurt, asks West; the white cop, no hero, responds with a crack about affirmative action. Elsewhere in the plot, a Native American trash-picker (played by the excellent Michael Greyeyes, a Canadian First Nations actor) appears first as a suspect in the crime and then as the driver of a tragic tangent.

“True Detective” springs, sprightly and with confident assurance, from a years-long absence. Its last episode aired in August 2015, a lifetime ago and a hiatus that saw HBO debut “Big Little Lies” and “Sharp Objects,” Jean-Marc Vallée’s two wild riffs on the mystery genre. The new season of “Detective” may not hit the operatic highs of those more bombastically edited series, but it’s a compelling and worthy example of a tradition that goes back even further than the first season of “Detective.” Like a good investigator, the show is methodically working a case. It’s digging through the kind of clues that were embedded in past seasons’ trajectories and in the mystery genre more broadly, and it produces clear evidence that a crime story, done simply and well — without elaborate thematic digressions or stuntiness — can punch above its weight even in a crowded TV landscape.

Taking the best of what’s come before and reinventing it in streamlined, unfussy fashion, “True Detective,” Season 3, cracks the case.

“True Detective,” season 3. HBO, Jan. 13. 60 min. Eight episodes (five screened for review). 

CREDITS: Executive producers: Nic Pizzolatto, Scott Stephens, Daniel Sackheim, Jeremy Saulnier, Steve Golin, Richard Brown, Bard Dorros.

Cast: Mahershala Ali, Carmen Ejogo, Stephen Dorff, Scoot McNairy, Ray Fisher, Sarah Gadon, Michael Greyeyes, Mamie Gummer, Deborah Ayorinde, Richard Meehan, Jon Tenney, Rhys Wakefield,