While political unrest roils the nation, left and right unite over a shared sense that nefarious elites are plotting to abuse and exploit us, their lessers. It is easy to dismiss these anxieties as delusional, their hosts as paranoiacs. But the trouble — and the great revelation of Ronan Farrow’s book “Catch and Kill” — is that the conspiracy theorists are essentially correct.

Farrow’s dark memoir of the era when he helped unearth the abuses of Harvey Weinstein unfolds like a classic noir. He opens on a suspicious conversation between a pair of criminals and then whisks the reader into his own world as it was then — surprisingly bleak and mottled with disappointment. Farrow depicts himself as an outsider, demoralized by the failure of his short-lived MSNBC program, “Ronan Farrow Daily,” and convinced that he lacks the cool and gravitas of the longtime TV journalists who surrounded him at NBC. He has his reasons for being especially concerned about issues regarding sexual abuse; at the outset, he remarks on the allegations his sister Dylan has made against his father, Woody Allen, and seems to suggest that they were formative for him.

A tone of cold dread sets in before Farrow realizes he’s in the presence of some truly despicable characters. Matt Lauer’s first appearance in the book, for instance, is subtly sinister — Farrow innocently observes as Lauer pushes a button on his desk and his office door swings shut. (The infamous button, for which a chapter is named, would eventually become a key feature in the sexual misconduct allegations against the former “Today” show host.) As Farrow begins digging into the Weinstein case, other dark threads unspool around him, including those involving Lauer. The network superiors seem indifferent to their anchor’s alleged abuse, and Farrow is soon navigating a web of deceit and intrigue spangled with the names of some of the media’s most powerful figures.

At the heart of every great noir is a conspiracy of evil that imbues the initial crime uncovered by the hero with a weightier resonance than was immediately obvious. So it goes with “Catch and Kill.” Weinstein turns out to be not only a sexually exploitative megalomaniac but also a thoroughly connected one, whose Rolodex of debtors, leeches and sycophants included the Clinton family, the Trump family and seemingly all of Hollywood. (In one stomach-turning episode, a wormy publicist trying to put Farrow off Weinstein’s trail calls to say that “Hillary Clinton had finished a greenroom conversation with Weinstein, her old friend and fund-raiser, then stepped onstage to give a speech at Women in the World.” Farrow is, fortunately, not dissuaded by the creep’s proximity to power.) When the army of connections enlisted to pressure Farrow fails to get him to drop the story, Weinstein turns to less-figurative militants — Black Cube, a private investigative agency staffed by former Israeli spooks, who give Farrow cause to fear for his life.

Observers of the weirder aspects of the news cycle might note similarities to Pizzagate, an invented scandal in which Clinton-linked operatives such as David Brock and John Podesta were alleged to have been involved in a child prostitution ring run out of the basement of a Washington pizza parlor. That was nonsense. But the scandal surrounding Jeffrey Epstein — the late financier of mysterious means who allegedly trafficked teenage girls for sex with him and his wealthy friends — was decidedly real and involved, peripherally or otherwise, a similar roster of rich and powerful characters, including Les Wexner, the mogul behind Victoria’s Secret; Britain’s Prince Andrew; and Bill Clinton. (Unsurprisingly, Epstein and Weinstein were at least acquaintances.)

By the time Farrow gets around to the allegations against Lauer — to which the former NBC anchor has now responded with vehement denial — one begins to wonder if all these conspiracies of exploitation are really parallel or whether they somehow intersect. Is it possible that Bill Cosby, Bryan Singer, Les Moonves, Epstein and Weinstein could have all simultaneously carried on years-long campaigns of sexual abuse in the claustrophobic, insular world of media without drawing upon the same resources? Or is the media — and by extension politics, its symbiotic partner — corrupt by its nature, structured by its own power brokers to permit victimization on a grand scale?

“Catch and Kill” has already resulted in precisely the sorts of legal threats and intimidation campaigns it details in its pages, suggesting that, at the very least, media moguls in the business of villainy share a playbook. Dylan Howard, an executive at American Media Inc. — the parent company of the National Enquirer, whose service of obtaining and burying incriminating stories for rich clients such as Weinstein and Trump gives the book its title — has sued Farrow and his publisher, Little, Brown and Company, to halt publication. Neither Farrow nor his publisher have shown signs of backing down.

That’s a good thing. Exposing the rot inside the media has had the simultaneous effect of discrediting journalism as a profession, which is perhaps the greatest unspoken reality of the #MeToo era. Journalists played an enormous role in uncovering these endless scandals, but the abuse by journalists themselves helped keep them submerged for as long as they were. (Farrow writes that Weinstein, for instance, used knowledge of Lauer’s alleged misconduct to suppress stories about his own foul play, which might otherwise have appeared on NBC.) It isn’t difficult to understand why ordinary people, reviewing a full accounting of the facts, might conclude that they can’t necessarily trust what they see — or don’t see — in the news.

Such is the great political crisis of these times. One can’t blame people for doubting the truth when there are so many well-publicized lies, and one can’t blame people for believing in conspiracy theories when there are so many conspiracies. Maybe these scandals are limited to particular spheres of influence — and maybe they’re not: How can one expect a rational onlooker to be certain, when those tasked with exposing the truth have themselves been exposed as liars?

Journalism like Farrow’s — fearless, exhaustive, even reckless in its disregard for personal or professional consequences — is the only way to begin to correct this problem. Still, even the noblest journalism can’t reverse the fact of what happened: namely, that some of the most influential people in our country have long perpetrated organized sex crimes against women and children. Farrow might be able to restore some faith in journalism, but restoring trust in the wide range of institutions implicated in these heinous scandals lies beyond the reach of a single book. Still, he does what he can — he bears witness, and offers a harrowing portrait of sin and depravity in the bleak tones they merit. If there is any lesson in noir, it’s that the darkness is always all around you.

CATCH AND KILL

Lies, Spies and a Conspiracy to Protect Predators

By Ronan Farrow

Little, Brown and Company. 464 pp. $30