The heat of active injustice helped Making a Murderer become a sensation for Netflix after an under-the-radar release in late 2015. It followed on the heels of other longform true crime stories like The Jinx and Serial that mobilized viewers around the perception that an in-progress legal miscarriage could still be corrected.

Netflix's seven-episode docuseries The Keepers will stir comparable feelings of outrage, mixed with the conflicted resignation of the passing of time. The crusading sense that vindication could come for a Brendan Dassey or Adnan Syed, that Robert Durst could still be held accountable, takes on a different meaning in a murder case that's 47 years old. The Keepers is fascinating and often gripping because it makes the argument that shining a light on enshrouded horrors takes many forms and doesn't have a statute of limitations, even if the law does.

The basic facts are these: In November 1969, Sister Cathy Cesnik, a nun and former beloved teacher at Archbishop Keough High School in Baltimore, went out to get a wedding present. She never returned. Two months later, her body was found. Around the same time, a second young woman, Joyce Malecki, was also murdered. Investigations, particularly into Sister Cathy's murder, stretched over multiple decades, but as the story being told by director Ryan White (The Case Against 8) begins, neither crime was solved.

White starts the series with two of the most unlikely gumshoes you could imagine, a team-up that's halfway between Murder, She Wrote and Father Dowling Mysteries, a duo you'd never see toplining a network show today because it would skew outside of the 18-49 demo. Gemma Hoskins and Abbie Schaub are in their 60s. They're both retired and have dedicated themselves largely to investigating the death of Sister Cathy, a favorite teacher from their youth. Abbie is more introverted and detail-oriented, an expert researcher. Gemma is more social, gifted at reading people and getting them to talk. At times, they're conspicuously low-tech. Their suspect board consists of labeled coffee filters with lines drawn between them. But they've also built up a passionate Facebook community of former classmates, crowdsourcing memories and clues, many shocked and relieved to have a voice and forum after so many years, to learn that they weren't alone in their nightmares.

This sexagenarian Cagney and Lacey is where White, executive producer Jessica Hargrave and the production team of Film 45 and Tripod Media begin The Keepers, but White and his team embark on what is presented as a simultaneous and generally complementary investigation in which sometimes the filmmakers seem to know things ahead of Abbie and Gemma, sometimes they seem to be letting the women lead the case and sometimes time itself brings revelations. 

It's initially a confident storytelling device. The oversized episodes — most stretching over an hour and several, to be candid, perhaps in need of a little trimming — give the impression of a case opening up gradually, even if White and his editors treat as twists and surprises a lot of details that clearly could have been revealed immediately and upfront if the goal were full disclosure rather than mystery. The second episode, for example, changes its focus to Jane Doe, whose story of being taken to Sister Cathy's body is only the start of a murky spiral that takes The Keepers deep into the realm of sexual abuse abetted and ignored by the establishment of the Catholic Church. As we progress, additional suspects are suggested and heartbreaking stories are told, stories that span decades.

The approach is more novelistic than journalistic, where an editor might accuse White of burying countless leads. Stylistically, the flourishes are limited. Black-and-white reenactments are more evocative than concrete representations of events and mostly they added little for me, though a couple haunting images popped. Blake Neely's score mostly knows well enough to let the interview subjects push the emotion.

All seven episodes were sent to critics, and it's illuminating to watch as White's approach loses focus or at least clarity in a way that I certainly assume is intentional. The series mirrors the elation of coming into a case in which certain things are known and certain figures are available and eager to talk and then running into the walls that kept this case unsolved for so long. There are tips that seem initially revelatory or thrilling, but turn into unresolved dead-ends. There are uncooperative lawyers and police officers and the inevitable stonewalling and obfuscation courtesy of the Church, which you know would never greet a series like this with an eager, "Oh, sure, we've got nothing to hide." The second case, that of Malecki, goes almost unmentioned for hours at a stretch. There are intimations of progress, but it's a realistic progress of misleading smoking guns and muddled hope. As was also the case with Making a Murderer, the temptation to just start Googling like a maniac to find out what has and hasn't happened becomes entirely irresistible, and I made it only through the fourth episode before my own need to research began.

The facts and the current status of the case are really only a small part of what makes The Keepers work. Leaving the predictably recalcitrant archdiocese out of it, White and his crew have received an amazing amount of access and cooperation, with interviews with dozens of former Keough students and Sister Cathy's former colleagues and people adjacent to various suspects and people of interest. The candor they exhibit is graphic, heartbreaking and, at times, very difficult to watch, even if you feel like you've seen enough documentaries and movies about the subject to have built up emotional calluses. The power of expurgation and honesty flows through The Keepers, even if it's constantly running into institutional obstruction. You can see how the mere act of speaking truth is vindication.

The Keepers is also about the pressure and limitations of memory and the vicious adversary that is time. White plays a little coy with which featured characters from the story are alive and who passed away taking secrets to the grave. He also sits patiently with subjects who either don't remember things that happened 40-plus years ago, or prefer to lie or misremember. Actually, he's only mostly patient. A couple times in later episodes either White or cinematographer John Benam can be heard trying to prod one particularly inert subject in a way that I don't think we'd tolerate if it were coming from a police officer or lawyer, but feels like a sincere frustration here.

There's courage, there's cowardice, there's stubbornness and there's ambiguity. To some degree, it's up to the audience to decide whose memories are trustworthy and whose are strategic, a not insignificant distinction as repressed memories come into play on a very public stage.

Some of the true crime hits that preceded The Keepers have launched a thousand Reddit threads as amateur sleuths attempted to play prosecutor or defense attorney, but this may not get quite that reaction. Too many of the people with the answers are dead or missing or restricted from talking. If the series is maybe less viscerally satisfying, it's probably more spiritually rich. Vengeance or even pure justice take a back seat to the relief and freedom of bringing light into darkness, but also the regret about stories too long forgotten and stories still left untold.

Premieres: Friday (Netflix)