The Gilded Age Season 4 premiere on HBO featured ruthless Pinkerton detectives, the birth of a baby, and a lavish society wedding. However, the storyline that might have stunned audiences the most actually took place in a small hotel room downtown under the cover of night.

**Spoilers for The Gilded Age Season 4 Episode 1 “Ring the Bells,” now streaming on HBO Max**

Marian Brook (Louisa Jacobson) not only found herself in a downtown dance hall having a good time in The Gilded Age Season 4 Episode 1 “Ring the Bells” — “Oh, downtown! Wow, that crazy club,” Gilded Age star Louisa Jacobson deadpanned to DECIDER — but she also gave into her long simmering passion for former flame Larry Russell (Harry Richardson).

That’s right: Larry and Marian didn’t renew their engagement, but they did have sex! (Which immediately sent Marian absolutely spiraling in shame.) So how did a character who was so uptight about Larry skipping Delmonico’s to go to a nightclub that she cancelled their wedding wind up in such a position? Blame Oscar (Blake Ritson) and Enid (Kelley Curran)?

When The Gilded Age Season 4 Episode 1 starts, most of New York society has braved a torrential downpour to attend the wedding of Oscar van Rhijn and Enid Winterton. The closeted gay man offered the former ladies’ maid-turned-wealthy widow a juicy proposal in the Season 3 finale. As a team, with his connections and her money, they could conquer New York and bend it to their will. Their first task as a newlyweds? Convincing the uptight Marian to join them at Webster Hall (which historically would not have been open for another year) for their wedding’s afterparty. Also at Webster Hall? Larry Russell. Soon, the two are dancing and the world falls away.

“Yeah, that was amazing to shoot,” Jacobson told DECIDER. “When we first got the script for the first episode, I was like, oh my gosh, what a great — even if it’s very fleeting — what a great moment we can see Marian sort of feel release and happiness and joy. Especially when they’re dancing and the slow-mo kicks in and you just really see her let go. I just, I could cry talking about it.”

Larry gallantly offers to help escort Marian home, but the storm wrecks their carriage. The only obvious solution? They’ll have to stay (in separate rooms) at a nearby hotel. While the former lovebirds are initially safely apart, Larry knocks on Marian’s door in the middle of the night. She opens the door and invites him in. The rest? Well…

Louisa Jacobson explained that it was important for The Gilded Age to lean into the “joy” and “passion” of Marian and Larry’s night so it would feel “harder…when the shame kicks in.”

“When the reality of the 19th century Victorian purity laws basically come crashing down on her the next morning and the realization that she could be turned out on the streets, destitute, no longer suitable for marriage, life prospects, all gone,” Jacobson said, literally shaking.

“She’s in a state of complete panic and when you’re in a state of panic you’re in fight-or-fight and you’re not ready to listen to anyone,” she said. “I think she felt the morning after she sees him in the bed, she knows that this is going to change only her life, not his… The feeling, realizing, knowing that he wasn’t going to face the same consequences makes her feel so alone.”

Jacobson was determined to explain the sudden shift in Marian’s mood because she understood how her Gilded Age character’s reaction could seem strange to our contemporary values.

“It’s difficult for a modern audience to understand that, but it was difficult for me as an actor, certainly, to unlearn all the things I know about sex,” she said. “Unlearn how it feels to be free to sleep with who I want — and I could list all these other things…”

“You played it really well,” Jacobson’s Gilded Age co-star Denée Benton said.

“And last night [at the Season 4 premiere screening], that modern audience certainly knew what was going on,” Gilded Age star Ben Ahlers said.

“When you were shaking,” Benton said, “we were shaking.”

“We get it,” Ahlers said. “In the sense that it’s so well executed by both of you.”

How will this affect #Larian going forward? Only God and Gilded Age showrunners Julian Fellowes and Sonja Warfield know!