OLIVER Emanuel is finding it difficult to see the wood for the trees at the moment. While his new play, The Monstrous Heart, was running at the Stephen Joseph Theatre in Scarborough prior to opening at the Traverse in Edinburgh next week, his partner gave birth to the couple’s second child. In the five days before we talk, Emanuel hasn’t had much sleep. The event does, however, give some kind of insight into his play, in which estranged mother and daughter Mag and Beth are reunited in a volatile fashion that lays bare all manner of demons waiting to pounce.

“I suppose this is quite a dangerous play,” says Emanuel, “and it’s designed to be like that. I wrote it with all switches turned to eleven. One of its starting points came about ten years ago when I was writing plays with young offenders in prison, and I became really interested in how these children were treated by the rest of society, and how in other people’s eyes they were just killers or thugs, which raised a lot of interesting questions.

“Then, about four or five years ago, I was about to become a dad for the first time. Me and my partner were really excited about it, and we were having a fish supper in Anstruther, and we started wondering what if it wasn’t the best bits of each of us that our child ended up with, but the worst bits. We made a list of all of our worst bits, and ended up thoroughly depressed.”

While Emanuel is keen to point out that despite his and his partner’s fears, their daughter has turned out “delightful”; he is also aware of future dangers pointed up in the play’s third influence.

“Frankenstein,” he says. “There’s a brilliant moment in Mary Shelley’s book where the creature wakes up, and Dr Frankenstein sees the horror he’s brought into the world, and makes a run for it. That makes you think about what the monster really is, and I think a lot of that came from Mary Shelley’s own life, which had a lot of abandonment in it, from when she was sent away when she was 13 to everything that happened afterwards.”

Emanuel has channelled all this into The Monstrous Heart in a way that allows his characters to vent in a suitably unhinged fashion as only a mother and daughter can do.

“They are a horror show,” he says. “They’re not characters you’d want to spend any time with in real life. There’s a lot of unfinished business there, and when Beth turns up at this cottage in the Canadian woods that Mag is living in, they haven’t seen each other for a very long time, and it’s like the moment in Frankenstein when the monster catches up with the Doctor.

“Beth is this funny, difficult woman, who’s been in and out of prison, and has this big physical presence onstage. Mag is very different, and is this very quiet, troubled woman, who’s really intelligent, but holds so much under the skin, and has moved out of society on purpose so she can be away from that environment.”

There is also the added element of a dead grizzly bear in Mag’s living room. How and why it ended up there remains to be seen, but the result is “a play about nature versus nurture, and how the past catches up with you,” according to Emanuel.

Whatever happened to the grizzly bear in The Monstrous Heart, animals of one sort or another have made frequent appearances in Emanuel’s plays, be it the eponymous fire-breathing creature in Dragon, the fish in The Day I Swapped My Dad for Two Goldfish, and the penguins in Spirit of Adventure, going right back to his early play, Magpie Park. Currently in development is a new play called I Am Tiger.

A raw animal mentality is certainly there in Mag and Beth, played in Gareth Nicholls’ production by Christine Entwisle and Charlene Boyd. Both actresses are forces of nature in their own right, with Entwisle having taken the lead role in the National Theatre of Scotland’s production of Anthony Neilson’s play, The Wonderful World of Dissocia, while Boyd has appeared in several productions by Grid Iron Theatre company, and played Lady Macbeth in the Citizens Theatre’s stripped-down take on Shakespeare in The Macbeths.

“They’re both such instinctive actors,” says Emanuel, “and they’re onstage throughout, so the play is like a wrestling match or a boxing match, and they have to build their performances, and see how they can score points off each other. It’s interesting as well that Christine and Charlene have physical resemblances, as even with that, children can be so different from their parents. My daughter is only three, and she looks like me, but she’s very different from me. That makes me ask questions about how she was made, and what shapes her as a person.”

In terms of The Monstrous Heart, Emanuel takes it to extremes.

“I guess what I’ve been thinking about when writing the play is about how we label people as monsters,” he says, “and whether there’s something inherent in us that might make us monsters, or whether it’s something that society does. I’ve always been interested in exploring what makes someone good, and what makes someone bad. Is it decisions we make, or is there something in our core being that makes that?”

The Monstrous Heart is at Traverse Theatre, Edinburgh, from October 23-November 2