David Morrissey's neighbours from hell
The anxiety first-time parenthood can create is transformed into suspense and horror in British psychological drama The Ones Below, as two couples living in the same London building have very different feelings towards having a baby.
One of its stars, Liverpudlian actor David Morrissey, believes "it's a film that will provoke a lot of discomfort. It's not full of shock horror things where people are jumping out of cupboards; it's not that type of horror film.
"It's more subtle than that, and psychologically disturbing, and that's what I like about it. It's a character-based film about people who are slightly on the edge, going to the dark side."
Also featuring the star of the TV series Birdsong, Clemence Poesy, Finnish actress Laura Birn and Stephen Campbell Moore, it's the feature film debut of David Farr, the Guildford-born stage director, who also wrote the current BBC TV adaptation of John Le Carre's The Night Manager.
"Many of us live in big cities and think we have a great social life, but when it comes to something as frightening and primal as giving birth for the first time, it can be quite an isolating experience," Farr comments.
"There's much less chance in our lives now, certainly if we live in the western world. We don't enjoy chance and we like to control things - and anxiety often surfaces within that gap, as there's a lot of chance involved in pregnancy and birth.
"The film explores the anxiety that eats and destroys and makes you susceptible to terrifying forces - it can be deeply insidious. All our energy that might once have gone into survival or into religion, often now finds focus in something very simple - in this case childbirth."
For that reason, Farr adds, he sets the film amongst the successful middle classes, "as only they have the luxury to be worrying about having children".
"If you have nothing and you have a large family, the chances are you won't have time for anxiety about your mental state. It's a complete critique of the modern middle class, of which I am a member."
Poesy and Campbell Moore play Kate and Justin, a successful 30-something couple who are expecting their first child, when new neighbours move in downstairs.
This couple, Jon and Teresa, played by Morrissey and Birn, are also expecting a baby, after trying for seven years. While having dinner in the upstairs flat, a terrible accident leads to Teresa losing her child.
"Both couples are completely traumatised by it," explains Morrissey.
"Our couple blame the people upstairs for what happened, and we leave the country to deal with the loss. In the meantime Kate and Justin have their baby, and they have to deal with their apprehensive feelings about starting a family, and we come back into their lives. But is it for good or bad? That's for the audience to decide."
Morrissey, who starred recently in the zombie horror TV series The Walking Dead, describes himself as "totally unnerved" by the atmosphere of The Ones Below.
"It explores the desire for children, the need for children and the idea that you're complete only when you have children.
"And then there's that other emotion where people don't know if they really want children, and they worry, and that's another truthful place."
Morrissey, the father of three grown-up children, adds that the film brought back memories for him of being "totally unprepared" for the arrival of his first child.
"My favourite moment on set was with the two little babies, who are just weeks old, who play Billy, the child of the couple upstairs.
"It's been wonderful to be with them myself and to hold them, it's just full of memories for me as well as nostalgia, as my kids are now either leaving or have left home.
"But it also reminded me of what my character doesn't have - he's desperate for a child, to have that connection and to be that person who can pass on everything he knows, to be a guide - to have basically the best bits of being a parent."
Roman Polanski's 1968 classic horror movie Rosemary's Baby, starring Mia Farrow, remains a benchmark for exploring paranoia around the birth of a child.
Farr says: "I wasn't thinking about it at all when I wrote it - I had the idea from a conversation with someone, but I knew that eventually it would be an ancestor I had to confront.
"I think Rosemary's Baby is more concerned with horror and the occult than The Ones Below, which is psychological suspense - but we certainly paid homage to the film in the soundtrack, and little touches, such as one of the nurseries - we felt we had to acknowledge it."
Morrissey calls The Ones Below "the kind of film the UK used to make and then gave it over to the US and Europe to do".
"We used to do these tense psychological thrillers very well and I feel it's a welcome return to that.
"It's an incredibly disturbing film. From my point of view, these themes of fatherhood, the desire to become a parent, are very powerful things. It's something you feel is your right, and when it doesn't happen, this film explores how it can tip you psychologically into a very dark place. Really, it's about desire and loss."
The Ones Below is released in the UK on 11 March.