Big ideas, detailed portrayals: Ryan McKinny as Gunther, Eric Halfvarson as Hagen and Daniel Brenna as Siegfried in “Twilight of the Gods.” (Scott Suchman/for Washington National Opera)

Opera is a monstrously expensive art form. The Washington National Opera’s “Ring” cycle cost $10 million to mount, and many people paid thousands of dollars to snag premium seats. All too often, the money yields only disappointment.

But by the end of “Twilight of the Gods,” the fourth opera in Wagner’s tetralogy, which wrapped up the first cycle at the Washington National Opera on Friday night, it was clear that, for once, the return on this huge investment is a genuinely important work of art. Francesca Zambello’s “Ring” cycle is strong and moving, thought-provoking and powerful, with musical performances and insightful directing supporting each other in an experience that will leave those who saw it thinking and savoring for a long time to come.

I wasn’t nearly as enthusiastic when I saw this production’s earlier form in San Francisco in 2011. One major difference is the conducting. Philippe Auguin, WNO’s music director, got things this week out of the Kennedy Center Opera House Orchestra that I don’t think anybody knew could be gotten. He projected throughout an air of serenity, conducting with a gentleness not always associated with Wagner, to the point of sometimes underplaying it. “Twilight of the Gods,” like the other three operas, was rife with moments of chamber-music delicacy that brought out the sheer beauty of the music and the sophistication of Wagner’s interweaving of his leitmotifs. And when Auguin did pull out all the stops — in, for instance, Siegfried’s Funeral March — it hit with shattering force.

Zambello’s direction, too, has come into sharper focus. This whole “Ring” negotiates the macro-micro divide with aplomb. It delivers crisp and detailed character portrayals, such as Melissa Citro’s evolution as Gutrune from a brassy bimbo testing out come-hither poses at the start of “Twilight” to her ultimate anguish as she witnesses and understands the world’s collapse. But this “Ring” also follows an overarching theme: the destruction of the planet by men focusing single-mindedly on the pursuit of gold.

Marcy Stonikas, Lindsay Ammann and Jamie Barton as The Norns in “Twilight of the Gods. Ring Cycle.” (Scott Suchman/For Washington National Opera)

The patness of Zambello’s original “American Ring” concept in 2006 — in which Nibelungs are slaves and Wotan is a capitalist — has proved the foundation for a more honest and even realistic commentary. By the end of the cycle, the forests are wastelands, the landscapes industrial jungles of cables, transformers (in the Norns scene) and grim smokestacks (when Gunther and his men, in paramilitary gear, go hunting). When the Rhinemaidens reappear in “Twilight of the Gods” (their singing still among this production’s highlights), their river is dry and choked with garbage. All of this is clarified and supported by beautiful videos, between the acts, by Jan Hartley and S. Katy Tucker, shifting from views of the forest (in “The Valkyrie”) to logging trains and parched earth and other elegant images of waste in “Twilight of the Gods.”

But the “Ring” isn’t just about big ideas. It’s about parents and children and the way they lovingly and not so lovingly thwart each other and try to play up their best intentions while getting entangled in their own selfishness. None of it, macro or micro, comes across without a strong cast, and this “Ring” offered that, too. Daniel Brenna’s Siegfried represented an important conceptual step forward from the 2011 staging: still raw and brash, but no longer a completely unlikable lout, with a strong voice and an ability to convey his character’s heroism in — especially — his death scene, standing upright for longer than seemed humanly possible, and singing with the same promise he showed in Wednesday’s “Siegfried.” Eric Halfvarson was a menacing if slightly cartoon-like villain as Hagen, and Ryan McKinny, vocally pale, was an appropriately wimpy Gunther. Jamie Barton was a warm presence as one of the impressive trio of Norns (the others were Lindsay Ammann and Marcy Stonikas) and Waltraute, who appeals to Brünnhilde to help save the gods who have already cast her out.

As Brünnhilde, Catherine Foster had the unenviable task of having to reclaim her own “Ring” after Christine Goerke triumphed as her substitute when a leg injury kept her from singing the first performance of “The Valkyrie.” She proved equal to it, representing the production with big, loud, triumphant singing on the one hand, and moments of sensitivity on the other, such as the second scene of “Twilight,” when she proudly sent Siegfried out into the world in search of adventure, and then, as soon as he was gone, curled over in the pain of abandonment.

Sensitivity, too, is needed for Zambello’s staging of the final scene, largely performed on an empty stage as the women gather to clean up the mess made by the men. Some of it is strikingly intimate given that this is thought of as one of the biggest scenes in all of opera. It’s staged as gentle power: women piling up garbage and pouring out gasoline to create the pyre, while, as Valhalla burns, the images of fallen warriors drift down over the stage, evoking the papers falling through the sky in New York City on Sept. 11, 2001. At the end, after the flames have abated, a child in white comes onstage bearing a green sapling, in a gesture as unabashedly naive and borderline kitschy and deeply moving as opera itself, while the orchestra pours out the hope of redemption.

At the end of the curtain calls, filled with shouts and bravos from the audience, the entire orchestra was revealed onstage for a well-deserved ovation. In light of these performances, it seems astonishing that Auguin is not widely acknowledged as one of today’s very best Wagner conductors, and equally astonishing that he is only conducting a single production at WNO next year before his contract expires. WNO might do well to take a lesson from its own “Ring”: Remember that the hero you seek is sometimes the person standing right in front of you.

The “Ring” cycle repeats twice more, through May 22.