In Knocking, a psychological thriller by Swedish director Frida Kempff, Molly (Cecilia Milocco) has been discharged from a mental institution, and her life is set to begin when she moves into a new apartment. But just as a heatwave sets in, her habitat turns menacing. There’s a strange, inexplicable knocking sound coming from the apartment above – or so Molly thinks. When she tries to uncover the ownership of the sound, none of her neighbors can hear it. Even her call to the authorities brings no relief. Have the ghosts of her past refused to leave her, and she is slowly going mad, or is she really witness to something foreboding? We spoke to the director and star to have them sound off.

What is it like to have your film at Sundance?

KEMPFF: I mean it’s the best, right? I mean it’s the best start that you can get as a filmmaker and with a film. I am so honored and so happy. It’s like I am having a happy shock.

What is fascinating about this film is how you play with the concept of the thriller. You really make this a psychological tightrope the audience has to walk.

KEMPFF: Yes, it might sound strange, but I actually never thought about it as a genre movie, I just was so into this woman’s story and her emotional journey. And I mean sometimes just being a woman can be dangerous and could be a genre in so many ways. So, I was just very true to Molly and her story and just believing in her.

Cecilia, what was your own journey into discovering Molly’s oath? We get a hint at the beginning and with the flashbacks regarding someone she cared about.

MILOCCO: Well, the thing that really occurred to me was the feeling when your own truth is slipping away, because that’s something we both shared, Frida and I with Molly and we talked a lot about that because that is an inner horror really when no one is there to support your experience or your own truth. And yes, she lost someone, and she lost maybe the only one that really connected to her, that really knew her. So yes, it’s also a story about grief and loss.

As we become aware of this knocking that Molly hears, evidence starts to mount that maybe it’s all in her head. How did you navigate that, so we are never sure if it’s real or hallucination?

MILOCCO: It’s like when no one is there, not even one person is there to say yeah you are right, yes, I hear it too, you have to have that dialogue with yourself. (laughs) So in the shooting that was also really fun but a challenge to have always that dialogue in yourself and that’s what’s very exciting with this Molly figure.

I do love how the story plays with our relationship to neighbors. Can we trust them? What is your own relationship to your neighbors?

KEMPFF: I have been moving around so much, so you hear a lot of sound for sure.  And I mean that itself is a horror because you never know. I remember there were a lot of fights in the apartment opposite me and I was listening to, is it really a fight, should I go in there, or is it just a regular fight or whatever? But actually, another story is that the editor lived in an apartment that we rented for her in Stockholm and she didn’t go out, she was just editing this movie, and she became almost paranoid. So, every time I went to hear every morning, she was just like, do you hear that? Someone knocked? I said no, you have been working too much, you need to get out, do something else. (laughs)

MILOCCO: Well, you mentioned that I now remember in my last apartment, there was always a man who said that I was disturbing or there was some disturbing noise from my apartment. I have two children so okay; it could be them. But sometimes he came down when I was alone, and he just said that it was like big steps and you can’t go like that. And I was like it’s not me, it has to be coming from somewhere else. And that is strange when you are in an apartment and the sounds, you don’t know really where they are coming from, the knocking too. You don’t know, is it there or there, right, left, you don’t know. And this man, he was determined that it was from my apartment.