Wandering around Joe Goldberg’s London flat, it feels like maybe the lonely sociopath has finally found refuge. The central character in Netflix’s You has hundreds of books, and not just on built-in shelves—they’re stacked on the floor, a coffee table, either side of the record player on the midcentury-modern credenza. There’s dark wood everywhere: Regency paneling, slatted floorboards, midcentury furniture, a window seat, Celestion C speakers for the record player, leather armchairs, and a fireplace. It’s all fitting for Penn Badgley’s character, who’s restyled himself as “Jonathan Moore” for season four.

When we left Joe at the end of You season three, he’d blown up his life in California—literally—and left for Europe. At the beginning of this season, the low-key serial killer has landed in London, where he’s found work as a writing professor. He swears he just wants to keep his head down and live a quiet life, but the man just can’t stay away from drama. Joe ends up an unwitting detective as he falls in with a group of wealthy British socialites who are being picked off one by one by a ruthless killer. 

On the show’s set last summer, I sat down with four of You’s brand-new cast members—Charlotte Ritchie (Kate), Lukas Gage (Adam), Tilly Keeper (Lady Phoebe), and Amy-Leigh Hickman (Nadia)—to talk about what it’s like to join a popular American TV show on their home turf, who they’re playing, and what we can expect from season four. Their leading man was there too—but what I discussed with him is top secret until part two of You season four drops March 9. (Part one, the first five episodes of the new season, premieres on Netflix Thursday.)

Charlotte Ritchie as Kate

“Her vibe is extremely guarded, a bit island-y, and very unemotional; she doesn’t let a lot of people in,” Ritchie says of her character, a no-bullshit gallerist who’s fiercely loyal to her friends but often the only one of them who acts like an adult. “She is hugely suspicious of Joe, almost to an extreme degree. She rejects him when he first appears on the scene. She doesn’t imagine that he’s there for anything other than a sinister purpose because she’s been trained to suspect people.”

You isn’t Ritchie’s first Netflix show. The London-native received critical acclaim for two seasons of the dramedy Feel Good, starring opposite Mae Martin and Lisa Kudrow. She’s also got a small role in the upcoming Wonka, the Charlie and the Chocolate Factory prequel starring Timothée Chalamet. Playing the fearsomely smart, independent Kate offered an exciting change of pace.

“I’ve come from doing quite a lot of comedy, and although this show definitely has a darkly comic streak, I think that the nature of the character […] is extremely mean and icy and serious,” Ritchie says. “So, that’s a real departure from the roles I’ve played. I have played one slightly sociopathic person who was rude but had a kind of humor to them. The nature of this show is just different and new [for me]—the subject matter is quite dark and grim.” Kate’s enviable wardrobe too has been a plus. “The level of glamor is something I’ve not experienced before and is a big adjustment for me in terms of self-image. The clothes are expensive and they’re uncomfortable; I’m wearing high heels all the time. She’s just very bold and strong.”

Tilly Keeper as Lady Phoebe and Amy-Leigh Hickman as Nadia

Though Keeper and Hickman’s characters—Phoebe is the richest member of an incredibly wealthy friend group, while Nadia is the star student who’s taken with Joe’s broody charisma—rarely share scenes on You, the two are best friends in real life. They met six years ago while auditioning for roles on Britain’s long-running soap EastEnders, both of which they snagged. “It’s very rare that you have a friend that you speak to every day, from job to job,” Hickman says. “We literally talk to each other every day.”

They don’t talk about absolutely everything, though. According to Keeper, neither told the other that she was auditioning for You.  “I remember I texted and asked if you wanted to come ‘round,” Hickman says. “And I was going to tell you then…”

“…and I didn’t want to come ‘round because I was so on edge about having just had my last meeting for this,” Keeper jumps in. “I was like, ‘I can’t. If I see you, I’m gonna tell you.’”

Hickman’s Nadia is a book nerd and proud of it. Growing up working class, she’s now a quick-witted literature major with dreams of becoming a serious author. “She doesn’t really have many friends at uni,” says Hickman, whose character befriends Professor Moore after seeing a bit of herself in his outsider status. “She’s there to learn and [feels like] everyone else is there to have a good time. And she’s not about that.”