The TV adaptation of Noughts and Crosses, the first novel in Malorie Blackman’s cult dystopian series for young adults, is one of the year’s most hotly anticipated new dramas.

Airing this month on BBC One, the six-part series, made by Mammoth Screen, boasts an impressive cast, including Helen Baxendale, Ian Hart and Paterson Joseph, and a cameo from Stormzy, who plays newspaper editor Kolawale.

Executive producer Preethi Mavahalli, whose credits include BBC Two’s NW, describes it as “an alternate-world show”, one in which white and black people are segregated, but the ruling class (the Crosses) is black and the white Noughts are subjugated.

At the heart of the narrative are childhood friends who become lovers, Sephy (Masali Baduza) and Callum (Jack Rowan). Sephy is a Cross and the daughter of a prominent politician. Callum is a Nought, whose mother used to work as a nanny for Sephy.

When their friendship starts to change, the pair embark on a passionate but dangerous romance. Their bond is put to the test by the pervasive racism and violence.

Mavahalli describes the adaptation as a long time coming – it was top of her priority list when she joined Mammoth Screen eight years ago but was not green-lit until 2016.

“I read the books when they came out and was a massive fan of them,” she says. “That’s how it all started, just from being a fan, having a passion for the book and wanting to get it made.”

However, Blackman was initially resistant to the idea. “Eight years ago, TV drama entertainment was very different to what it is today, with its increased ambitions,” explains Mavahalli. But, once the author agreed to sell the rights, she notes that the BBC was on board straight away: “At the time, Ben Stephenson [who left the BBC five years ago] was in charge of drama and was a fan of the book. As soon as he knew we had the rights, he was very keen for us to develop it. From day one, the BBC has championed it.”

Finding the right tone for the show was crucial. “I think it’s always been a really bold and provocative premise. To really pull it off needed a lot of time and money,” argues Mavahalli. “Expectations from the audience get bigger and bigger and we needed to deliver on that.” The books also have a broad and vocal fan base, as well as being national curriculum recommended texts for English.

Director Koby Adom – whose short Haircut was longlisted for a Bafta – helped to create the world imagined by Blackman, and has directed three of the six episodes.

Having read the novels as a child, the story had personal resonance for him. “There’s a lot of things in the book which I think were magical, and informed me as a person, as a black man, growing up in London,” says Adom. “Reading the books and the scripts [written by Lydia Adetunji, Nathaniel Price and Rachel De-Lahay], it’s scary how accurate some of these presentations are.”

Mavahalli says that it was important to keep “the spirit of the book” but, inevitably, changes had to be made for it to work on the small screen.

Although much of the series was shot in South Africa, the show is set in an alternate London, whose visual style was developed by Mavahalli and the team.

Adom recalls that he watched a lot of TV that could feed into his approach to the series. His research took in the intricacies of Nigerian culture, costumes, village life – and even masks – which he wanted to inform the Cross world. A court scene shows these influences: “There is no jury, there are elders, and everyone is wearing African attire, rather than a judge in a wig and gown.”

"What’s tragic is that [these themes are] more relevant than ever"

For the love story between Sephy and Callum, Adom wanted to focus on the claustrophobic and suffocating nature of their relationship, but also on its warmth and intimacy. “It was about getting the nuances of the emotions, not just having nice visuals but visuals that apply to the story,” he says.

Mavahalli suggests that the couple’s relationship has a universality that goes beyond race and class: “Some people might connect with the story for very political reasons, because of the exploration of racism and injustice, but you could just watch it as two people who aren’t allowed to be together.”

She insists, however, that the series is not trying to convey an overtly political message: “The world we’ve created draws in post-slavery [conditions] in the civil rights movement in the US, apartheid in South Africa and British colonialism. It’s not about one specific experience of what is to be a minority or what it is to be oppressed.”

When she wrote the novels, almost 20 years ago, Blackman assumed that they would be irrelevant by the 2020s, and told Mavahalli this. “I think what’s tragic is that it’s more relevant than ever,” says the producer. “Divisions, prejudice and racism are big issues and talked about even more than they were 20 years ago.”

For Adom, directing such a large-scale project before he turned 30 was a big step: “As a black guy, I’ve never seen a director who looks remotely like me.… After doing it, I had this huge feeling of achievement and fulfilment.

“[The cast and crew] didn’t expect this guy to be standing there with his durag and his slippers,” he laughs. “I had to rise to the challenge and have a vision for them to latch on to. If you’re not confident, your vision can be squashed.

“You have to be really confident in yourself. That comes from my relationship with God. I focused on what I know I can do and let God do the rest. My faith drove me through all the obstacles and here we are, I’ve finished three episodes of TV for BBC One.”

As for Stormzy’s involvement, the rapper told Blackman that as soon as he heard Noughts & Crosses was being adapted for TV, he was eager to have a part.

“Stormzy’s passion is just unrelenting,” says Mavahalli. “He is a huge fan and, of course, we wanted him involved. We flew him out to Cape Town. Apart from us, nobody knew about it. He did the shoot and then we announced it.”

Mavahalli hopes the book’s many other fans agree that the production has done justice to Blackman’s story.

Adom says he would be pleased if the show not only entertains but also sparks conversation. “Personally, I don’t really see it in a racial sense. What I think Noughts & Crosses does is start to humanise people.”

With the novels so close to so many people’s hearts, the TV series inevitably carries a heavy load as it introduces fans, both new and old, to a world quite unlike their own, but one with love at its centre.