Gugu Mbatha-Raw does a lot of running around San Francisco in the new Apple TV+ psychological thriller “Surface,” an eight-episode series premiering Friday, July 29.

Early in the morning and late at night, always dressed in a black crop top and leggings, the British actress, who shot “Surface” in San Francisco and Vancouver last year, cuts a stylish figure jogging down Waller Street and through the Haight, across Crissy Field to Fort Point and through Chinatown.

Mbatha-Raw (“The Morning Show,” “Loki”), who plays the series lead, Sophie Ellis, and is also executive producer, has the troubled look on her face of someone hell-bent on going on a run to clear her head.

The only problem is that Sophie’s head is already clear — in the devastatingly wrong way.

In the first episode, she wakes up in the hospital to discover she suffered a traumatic brain injury after jumping from a San Francisco Bay ferry. She has extreme memory loss from the supposed suicide attempt.

Sophie returns to her elegant Victorian home and unfamiliar life feeling confused, vulnerable and unsure who to trust — her venture capitalist husband, James (played by Oliver Jackson-Cohen)? Her multimillionaire best friend, Caroline (Ari Graynor)? Maybe the detective and former lover (Stephan James) who suspects Sophie didn’t jump but was pushed?

“Sophie can’t trust her own instincts because her past is a haze, so she has to become the detective of her own life,” Mbatha-Raw said during a video call with The Chronicle from New York about the new series she loves for its “central question about identity: If everything we remember gets wiped, are we destined to make the same mistakes?”

This conversation has been edited for clarity and length.

Q: “Surface” has terrific tension and keeps us guessing who to believe about Sophie’s past. Was it a page-turner when you read it?

A:Yeah, what drew me in is that even within the genre of the psychological thriller, this felt really fresh, and it genuinely kept me guessing. I can usually spot twists and turns, but the caliber of the writing by Veronica West made me question who to trust every episode. It had me on the edge of my seat in a nuanced and stylish way, which I really liked.

Q: What was challenging about playing a character without memories, who has no backstory to fall back on?

A:I love that as the show goes along, Sophie’s constantly looking at different people to tell her who she is. In episode two, when she and Caroline go off on the girls trip, she’s genuinely looking to Caroline to tell her what she was like. Yet, even with best friends, we all have parts of ourselves that we either don’t share or can’t share, and that’s fascinating to me.

Q: How did you like filming in San Francisco? It looks like you went running through the entire city.

A:We’d been in San Francisco in our minds for so long, it was special and quite emotional to finally be there in person. It’s just so iconic: the atmosphere, the foggy mornings. I love some of the noir elements of the show that we got by filming in Chinatown, for example, which has so much texture.

Running those streets and up those hills gave us a sense of authenticity but, honestly, our hotel was at the top of a mountain (laughs). I’m not kidding. We were based on Nob Hill, and I remember questioning, do I want to go down the hill to go to the pharmacy? My God, have I got the energy to walk back a block?

Q: Sophie’s house is a Victorian in the Haight, right?

A:Yes! And the fact that it’s the only black house on the street tells you there’s something sort of dark going on in this marriage. With its staircases and shadows, it perfectly captured the (show’s) Hitchcockian mood.

Q: That house is also a great embodiment of how opulent things can be on the outside, but still empty on the inside if you don’t know yourself.

A:Yes, Sophie has this closet of dreams and designer handbags, but underneath the surface there’s a lot that’s not right. If her life really was that perfect, then the essential question is, “Why did she try to end it by jumping off that ferry?”

问:你似乎有一个very upbeat personality. Do you enjoy doing dark and twisty dramas like this?

A:None of us are all one thing, right? We’re all far more layered than the personas we present. That’s what I love about acting, that you get to play multifaceted characters who are so interesting emotionally, and also intellectually.

That doesn’t mean it’s easy, and you can’t do it all the time. I just finished an art heist action movie with Kevin Hart (“Lift”), which was a nice palate cleanser after two psychological thrillers back to back. And I just started working on the second season of (the Disney+ Marvel series) “Loki” in London.

But consciously or not, I’ve always been drawn to dark things ever since I was a child. I loved reading Roald Dahl stories. I think it’s human nature to explore the macabre — from a safe distance.

Q: If, God forbid, you were to lose your memory, who would you trust to fill you in on who you are?

A:Keep this recording, for sure. (laughs) We might need to reboot it. Luckily, as an actor I’ve done a bunch of press so there are all these recordings. People could show me things I’ve said.

Joking aside, it must be absolutely terrifying to really be in that situation. And I think in some ways more difficult for the people that you knew before. If you weren’t a particularly nice person or you did bad things, how much should they tell you? It’s a juicy moral dilemma, isn’t it?

“Surface”(TV-MA) premieres Friday, July 29, on Apple TV+ with the first three episodes. Subsequent episodes released weekly through Sept. 2.