Of course, we’re talking about the actors who played them — a bevy of alumni from HBO’s celebrated series about a family of vicious corporate cutthroats — all at once taking their newly burnished fame back to the arena where many of them got their starts.

And at Broadway’s Circle in the Square Theatre, Jeremy Strong, after four seasons as high-strung Kendall, is now the impossibly high-minded Dr. Stockmann in a revival of Henrik Ibsen’s “An Enemy of the People.”

A hit series can supply an actor with newfound clout, but those who make indelible impressions on TV or film sometimes run into resistance from audiences unable to accept them as anyone else. (In PBS’s recently premiered “Nolly,” for instance, Helena Bonham Carter portrays one such unfortunate, Noele Gordon, a real-life British TV star who languished after being axed from her popular soap.)

It may be no coincidence, then, that for their post-“Succession” stage bows, Snook, Cox and Strong all chose well-known titles. The common practice these days for many movie and TV stars is to take artistic pressure off themselves by leaning on the brand-name renown of a classic play or musical. There’s something of a safety net in an alliance with a work of certified heft.

Several other “Succession” regular and recurring actors are back onstage in splendid form, a reflection of how richly the show depended on pros with theater backgrounds: Natalie Gold, who played Kendall’s wife Rava, in a meaty part in the Broadway comedy-drama “Appropriate”; Juliana Canfield, who was Jess, Kendall’s assistant, in the critically lauded “Stereophonic,” which has transferred to Broadway; and Peter Friedman, the simpering Waystar lackey Frank Vernon, who just finished a run in the off-Broadway thriller “Job.”

Experiencing their next acts was irresistible to a Successionista like me who was transfixed by the risible misery the series stirred up, courtesy of creator Jesse Armstrong. With images dancing in my head of untrustworthy Shiv, relentless Kendall and bombastic Logan, I set off on two continents to assess how they fared in the footlights.

Sarah Snook in ‘The Picture of Dorian Gray’

As it happens, playing Shiv revealed only something like 1/27th of the Australian actress’s range. This becomes evident as you watch her play 26 characters in a captivating stage version of Wilde’s 1890 novella, about an English bon vivant whose portrait mysteriously ages even as he remains eternally young.

Kip Williams, the adapter and director, has devised a remarkable vehicle for Snook — so dazzlingly, technologically ambitious you’ll think at times that you’re gazing into theater’s future. The implements are familiar: live video, recorded performances, quick costume changes. But the way they’re orchestrated feels almost revolutionary.

On what resembles a utilitarian soundstage, Williams unleashes a team of 14 videographers and stagehands, who assist Snook in the illusion that she is everyone and everywhere in Wilde’s tale.

Wilde himself would have been tickled by the wizardry that allows Snook to be projected live onto screens alongside prerecorded images of herself as the various fops, dowagers and servants in the story. In an uproarious dinner scene, the filmed visages of Snook in different costumes by Marg Horwell and wig and hair designs by Nick Eynaud sit side by side by side on a sofa. The technical sleight of hand is a triumph shared by video designer David Bergman and lighting designer Nick Schlieper.

And of course, there’s the astonishing Snook, who wears the vanity of Dorian himself with the baroque air of malevolent self-satisfaction. For in this gothic tale about the poisonous worship of youth and beauty, the exhilaration is all in how deftly Snook and company critique values that are only skin-deep.

“It is not good for one’s morals to watch bad acting,” avers Snook as the story’s witty Lord Henry Wotton. If that is the case, one’s morals will definitely be improved by this “Dorian Gray.”

Brian Cox in ‘Long Day’s Journey Into Night’

Cox was an established stage and film luminary long before he became the brutish paterfamilias of “Succession,” who makes a two-word epithet that begins with “F” and ends with “off” the trademark of his coarseness. Dozens of years ago, I saw him at the Royal Shakespeare Company in a peerless production of George Bernard Shaw’s “Misalliance,” and also onstage in New York in O’Neill’s psychological marathon “Strange Interlude” with Glenda Jackson.

So of the “Succession” stars, he’s made the likeliest leap, to a role he was destined to play: the washed-up actor at the source of the endless recriminations in “Long Day’s Journey.” It’s widely thought of as O’Neill’s masterpiece. But among canonical plays, it is also one of the most exacting. As a clinical psychological autopsy of a terminally damaged American family, the work requires a balance of personality and emotional temperature that can be monumentally difficult to achieve.

The revival directed by Jeremy Herrin at Wyndham’s features Cox and Patricia Clarkson portraying the benighted James and Mary Tyrone, with Daryl McCormack playing dissolute older son Jamie and Laurie Kynaston as sickly Edmund. When I saw it early in the run, the actors had not yet found the resonant domestic fissures; they had yet to fully embody the wounds, the resentments, the guilts that propel the Tyrones through cycles of lashing out and regretting.

The irony of Cox’s career trajectory is not lost on us, as he has gone from playing one of the world’s richest men to one of its stingiest: There’s Cox’s James climbing atop the Tyrones’ dining room table in the early 20th century, twisting on the chandelier bulbs to try to prove he is not the skinflint his family perceives him to be.

Logan’s characteristic bark, though, had not yet evaporated from Cox’s arsenal; he seemed only at the start of a transformation, of absorbing James’s disappointment in his one-note acting career, in his wife’s drug addiction, in his sons’ lost promise. Could it be that the temperament lauded in a previous portrayal was hard for Cox to leave behind? Or was my memory too freighted with his great TV performance? I may have to return to London to see if his James evolves.

Jeremy Strong in ‘An Enemy of the People’

Kendall was such a pill: the least-likable Roy, a tortured misfit, bullied by his father and haunted by thwarted ambition. Strong comes across in that performance as emotionally cold, which was perfect for Kendall, a stunted nepo baby who seemed to have to force himself to display family feeling, or even camaraderie.

The sense that more may be going on with Strong than what’s on the surface works fairly well at times for his Dr. Stockmann. He’s the admirably rational medical director of the town spa in Ibsen’s 1882 “Enemy,” who discovers the pollution of the water system that everyone else in the tourist town wants him to shut up about.

Stockmann is a truth-teller regarding the health threat the poisoned river poses, but the violent opposition to his financially ruinous findings turns him sour on humanity. This is a key factor in Ibsen’s original script, epitomized by Stockmann’s rant in the community meeting scene, when he uses the language of eugenics to denounce the cowardly “solid majority.” Stockmann can be, it seems, both presciently right and catastrophically wrong.

But in the Broadway revival directed by Sam Gold and adapted by Amy Herzog, Stockmann has been sanitized: The offensive tirade that seals his branding as an enemy is neutered, and so is the nuance. Now he’s an unassailable hero and a sentimentalized widower to boot: Gold and Herzog have killed off his wife, Katherine.

Perhaps Americans need heroes now without tragic flaws — or maybe Strong, emerging from Kendall’s neurotic clutches, was attracted to the idea of a purely courageous protagonist. I think he deserved a crack at the more complex character Ibsen put on the page. Because this pedestrian “Enemy of the People” does a disservice to both a great playwright and audiences who crave truly nutritious food for thought.

An audience gets a visceral kick out of seeing an actor in three dimensions, after bonding with them in two. What else accounts for that most absurd of theater phenomena, entrance applause? It’s a weird out-of-context acknowledgment of a performer in a show — who hasn’t even done anything yet!

But we’ve been conditioned to worship celebrity; becoming one brings fans’ hands reflexively together. In some cases, this accrues beneficially to the employment possibilities for a fine artist: Without “Succession,” it is doubtful that Sarah Snook or Jeremy Strong would see their names featured more prominently in ads for a show than those of Oscar Wilde or Henrik Ibsen.

So let’s give these actors’ returns to the stage a more positive spin: Without a TV success such as “Succession,” the works of giants like Wilde or Ibsen or O’Neill might not garner feverish Broadway or West End attention anymore. That’s a dividend that Waystar Royco and the rapacious Roys are continuing to pay out, long after the finale.