WHEN, in 2014, Laura Lam won the Bisexual Book Award for Speculative Fiction, she had only just started to acknowledge that she was herself bisexual. An American, she had married young the Scottish boy she had met over the internet as a teenager and had barely dated at all.

So when she invented the protagonist of her young adult series of books, an intersex, bisexual circus performer called Micah Grey, she had not yet recognised or acknowledged her own sexuality. It was writing that brought that revelation to her. “I think I ended up working it out unconsciously through my fiction. After I wrote four books with bisexual protagonists I was like, ‘Wait a minute, oh I see’.”

Lam is not, however, particularly interested in writing books about “bisexual white women” like her. What she wants, she says, is to tell, more widely, “the stories of the marginalised”. Such as the tale, in the Micah Grey series, of someone born intersex and forced to live as a girl, who moves between the two gender identities. Or the story, in her latest book, False Hearts, her debut adult thriller, of two formerly conjoined twins, now separated, one of whom is accused of murder.

Her next novel, she says, will revolve around a trans man. All are set in futuristic or fantastic worlds of speculative fiction. It is a genre that has provided some of the most imaginative enquiries into gender and identity, from Ursula Le Guin’s The Left Hand of Darkness to Iain M Banks’s creation of The Culture.

Such “diverse fiction” writing can sometimes be politically controversial. Some, she notes, suggest that writers like her should “stay in their lane”, and write only about what they know. But Lam feels driven to reflect the lives of those whose experiences are not often told. “We’ve had so many books about straight white men,” she says. “So I’m not as interested in telling another story about them or a character who is really similar to me. I find it more exciting to write about different kinds of people. It ends up being a lot more research, because it’s not your lived experience and you don’t want to fall into stereotypes or misrepresent them.”

THAT’S not to say Lam’s own life wouldn’t make a compelling plot, or that she doesn’t seem a little outside the mainstream herself. The author, who now lives in Aberdeen, was born in the 1980s to hippies from Haight Ashbury, the original Summer of Love colony in San Francisco. Her father, she says, “had 4ft long hair at one point in his life and smoked pot I think every day – since he was 13-years-old pretty much”.

She grew up in the alternative religion of Religious Science, a positive thinking movement.

Her family was complicated. As well as a brother four years younger, she has two siblings, from her father’s side, who are 22 and 26 years older than her. “The oldest one,” she says, “was adopted out because my dad had knocked up a 13-year-old when he was 16.” But it was also a hugely creative environment. “My dad was a total dreamer and he would always say, ‘Be whatever you want.’ But he also never held down a steady job or had any sort of financial stability. Whereas my mum was like, ‘Do whatever you want. But make sure you can pay your bills’. My parents divorced when I was quite young. Mum was a single parent and worked really hard.”

SHE recalls 2014 as a rollercoaster period. It was the year in which, despite the great reviews her Micah Grey series was getting, her publisher turned down the third of the trilogy, leaving Lam “devastated”. But it was also when the buzz started around her, a year in which her agent sold False Hearts, within nine days of sending it out, as part of a two-book six-figure deal.

At the time she was working in Aberdeen as “a document controller for an engineering agency”, a job in which, she says, she “looked over reports and made sure they were formatted correctly and the right people had signed them off and then emailed them to the client and saved that email to a database.” She immediately quit that job.

False Hearts was inspired by an article she read on conjoined twins Daisy and Violet Hilton, who were famous in the vaudeville era. “They were like the Olsen twins of the time and they were joined at the hip,” she explains. They also appeared in a few films. One, Chained For Life, featured a plot where one twin had killed the other twin’s boyfriend and they were both put on trial. It was this, says Lam, that sparked the idea for False Hearts. “I thought, what if your literal other half has a secret from you? And what if you would swear that there is no way your other half would commit murder? And what if they did?”

Lam’s father died last year and False Hearts is dedicated to him. Some of that hippie culture he raised her in is incorporated in the book. Mana’s Hearth, the community her twins are raised in is a version of Religious Science, but twisted and made sinister.

“I thought what if someone took this really laid back, sweet religion that doesn’t hurt anyone and twisted it for their own gain, what would that look like?”

When Pantomime, her first Micah Grey novel, sold in 2012, she recalls, people talked about it as a “niche book” because its protagonist was gender fluid and intersex. But it’s a sign of changing times in the market and society that it’s no longer perceived that way.

“Now I can say that my protagonist is intersex and people know what that means. Things and times have changed. There are also a lot more LGBTQI books coming out now and they are being given a marketing push.

”False Hearts by Laura Lam is published by Macmillan, priced £12.99