SPOILER ALERT: Do not read if you have not seen the April 2 episode of “Homeland.”

“R for Romeo,” the penultimate episode of “Homeland’s” sixth season, is packed with fiery moments that allow every key player in the ensemble to shine as the end draws near.

The hour is also stocked with of-the-moment observations on the cottage industry of fake news, the maelstrom of hate on social media, the responsibility of mainstream journalists, the demonizing of political opponents, and the struggle to separate alternative facts from fiction. “Deep state,” “deplorables,” and “Not My President” are buzzwords referenced in contexts that are only slightly removed from our real-life political discourse. This episode is painful to watch in that regard.

The episode is smartly written, by Chip Johannessen and Patrick Harbinson, to avoid proselytizing — even when President-elect Elizabeth Keane (Elizabeth Marvel) is speechifying at her press conference and in her verbal firefight with the creepy conservative firebrand Brett O’Keefe (Jake Weber). Marvel and Weber will surely be submitting this episode on their Emmy reels.

The direction by Seith Mann is fantastic. There’s a lengthy sequence with Carrie Mathison (Claire Danes) and Peter Quinn (Rupert Friend) that makes chilling use of darkness to build tension. By the end of the episode, the threads of the conspiracy that has been unfolding around Carrie are mostly pulled together. This leaves our central hero in the familiar position of having to hurl herself over roadblocks and obstacles to stop something bad from happening.

“Homeland” has had a lot to say this season about domestic politics and policy in the United States. It has taken on the Trumpian notion of the “deep state” in its own way, examining the scope and the motivations of the national security industrial complex that has metastasized since 9/11. The casting of CIA honcho Dar Adal (played with such verve by F. Murray Abraham) as the chief villain this season has strained credulity at times. But leave it to “Homeland” to predict real life before it happens. Adal’s off-the-books campaign to scare the President-elect into reversing her policy plans regarding the war on terror is indicative of Beltway battles now over the Trump administration’s priorities.

“Homeland” this season has also gone right to the heart of the warfare raging in the theater of public opinion. Brett O’Keefe and the boiler room of social media trolls that he directs — apparently with some covert CIA funding — reflects the ugliness and lunacy of political discourse on the far left and far right. Political opponents are criminalized, if not demonized. As many social observers have noted, there is no way to have a reasoned debate about tough issues like health care or immigration if the sides can’t agree on empirical facts that should inform decisions. In the age of instantaneous communications, there’s almost too much information out there to reasonably process.

“You are entitled to your own opinions but you are not entitled to your own facts,” Keane intones at the rowdy press conference she called to defend her late son’s honor after O’Keefe’s viral video “Cowardice Runs in the Family” smear of his military record was unleashed in last week’s episode. That line wouldn’t have resonated so much a year ago.

Keane at her news conference calls on the miscreants behind the video to come forward. O’Keefe does, and that leads to an on-air showdown in his studio. The improbable move comes on the advise of Saul Berenson (Mandy Patinkin), who seems to have become Keane’s most trusted adviser. Saul likens the fake news attack against Keane and her son to propaganda campaigns used to destabilize Third World governments. “It’s what we did in Nicaragua, Chile, and the Congo and back to Iran in the 1950s,” he tells Keane. “It does not end well for the elected regime.”

Another powerful aspect of this episode is how it zeroes in on the fury in the culture at present and the coarsening of public discourse. The throngs of protesters that Keane faces outside of her hotel are more than impassioned activists. Some of them are unhinged, likening her to Hitler. Keane is shaken by the display of unbridled aggression when a protester is hit while trying to rush her moving SUV. More than once this season, Keane has stated in frustration “60 million people voted for me” to express her disbelief at the violent reaction to her election. Love him or hate him, you can’t deny that the circumstances are much the same for our polarizing Commander in Chief.

“R for Romeo” succeeds in offering a commentary on the most troubling aspects of our political culture. It’s idealistic, for sure, but amid the swirl of suspicion about the influence of Russian hackers and oligarchs on the 2016 election, it’s a welcome fantasy. “In my government, truth will have a value and you will have no place,” Keane tells O’Keefe.

As much as it tackles the Big Picture, this episode also pivots to deliver incredibly intimate and important moments between star-crossed non-lovers Carrie and Quinn. Quinn finally confronts Carrie about her decision to rouse him from a coma back in Berlin, which led to his stroke. The two are holed up in a house next door to the Queens safe house for the CIA’s bad guys, a place Quinn knows well. Quinn is watching their movements through the scope of a semi-automatic rifle.

Quinn twists the knife in Carrie by describing his debilitated state as making him feel like a “monkey.” He runs around making screeching sounds and simian gestures to prove his point. At this sight, Carrie seems to realize the depth of his emotional damage. Maybe she’s also remembering the tenderness in the letter that Quinn left for her in Berlin. Quinn certainly does.

“It’s always the mission, the mission, the mission,” Quinn spits at Carrie, with exasperation.

It takes Carrie until the next morning to respond. She tries to stop Quinn from leaving to get his vengeance over the burly CIA bad guy who killed Astrid.

“It’s not just the mission, it never has been,” Carrie says, not quite convincingly. Quinn’s no fool.

“You gotta let me go,” he says, quietly, and she does.

Of course, this being Carrie and Quinn, within a few minutes, Quinn is back to save her from the attack by burly bad guy after Carrie enters the safe house in search of evidence.

Quinn lets his rage out by savagely killing the guy by beating him in the head with the butt of his gun. It’s animalistic, a release for Quinn that Carrie can’t stop. Afterward, Quinn fills Carrie in about Astrid’s death, and he forgives her for the coma business. He describes himself as an empty-hearted killing machine, to which Carrie replies: “Shut the f—- up,” which makes for another weirdly candid moment between the two.

“You didn’t do anything,” he tells her. “I’ve always been this way.”

Even in death, burly guy has one last trick up his bloody sleeve. He booby traps the garage containing the key hunk of evidence — a delivery van — that can nail Dar Adal et al for their murderous effort to foment fear and protect law the intelligence community’s carte blanche in the name of protecting the country from terrorist attacks.

The garage blows just after Carrie and Quinn figure out that the group of CIA bad guys were heading not to the Middle East but to Midtown Manhattan, presumably to wreak havoc with President-elect Keane. Carrie tries to warn Keane’s team that the “reinforcements” they are expecting may actually be a danger to Keane, but the fireball gets in the way.

Carrie reacts with much more conviction when she sees that Quinn survived the blast. And then they spread out to tend to the other victims.

With one more episode to go, here are some thoughts about plot threads still hanging:

  • This week’s Max storyline leads to the revelation that O’Keefe, unbeknownst to Dar, has used Quinn’s name and likeness to create a fake online profile of a rabid Keane-hater. How does O’Keefe know about Quinn, a man who doesn’t even use email?
  • What will become of Franny? Carrie’s adventures of the past few days certainly won’t play well in family court as Carrie seeks to regain her rights as a mother. Assuming she’s not taken out, look for Keane to grease the wheels here.
  • Where in the world is Majid Javadi? Last we saw him, the Iranian turncoat (times two) was being hauled off by Mossad after the double-cross by Dar. I suspect the wily Major General will be back in the finale.
  • Given the sudden warmth between Saul and Keane, it seems just a matter of time before Saul will be named CIA chief or at least a powerful No. 2.
  • How soon after that will Carrie be back in the agency? It’s time to plant the seeds of season seven, after all.