Six years ago, author Miriam Halahmy met with an unwelcome plot twist. She had a contract for a three-part cycle of novels for teenagers, set on Hayling Island; two had been published by Meadowside Books — then the company closed down.

“I was devastated,” she says. “Suddenly I was a Carnegie-nominated author without a publisher or an agent and three books on my hands.”

In fact, within three months, she had signed with agent Anne Clark, whose “fresh approach was very inspiring”. Yet “writing into the dark”, without the affirmation of publication, was not easy. “I had manuscripts piling up and no contracts. But deep inside me I believed I had something worth saying and that, one day, someone would recognise that again. Then the contracts started rolling in, for both the UK and America. I was a proper writer, not an impostor!”

American publisher, Holiday House, took two books — Hidden, the first Hayling Island book, about teenagers who find a half-drowned refugee on the beach, and Behind Closed Doors, which explores the reasons why teenage girls become homeless. Thrown together by a crisis, Tasha is sofa-surfing to escape her mother’s predatory boyfriend, while Josie is fending for herself amid the black sacks of her mother’s obsessive-compulsive hoard.

Halahmy dates the inspiration for Behind Closed Doors to 1966 when, as a sixth former, she watched Cathy Come Home, a TV drama about a couple who become homeless. Volunteering for homelessness charities has been an important part of her life. For the book, she also drew on memories of a hoarder in her own street. “Meals on wheels would deliver and she would eat on the doorstep, out of the silver container… I started to think what it would be like to be a child growing up with that.”

The book was published by Firefly in the UK last week. Meanwhile, in America, Hidden became a Junior Library Guild pick and was chosen by Scholastic for its book clubs.

“Interest in Hidden grew with the terrible refugee crisis and people crossing the Mediterranean,” says Halahmy, whose own grandfather walked through Europe from Lodz to take refuge in England (the story goes that this was his second arrival; the first time, he took one look at the fog and turned back). The book has now been reissued in the UK by Troika, with the rest of the cycle to follow.

Hidden has also become a play, scripted by Vickie Donoghue and directed by Stuart Mullins. It will tour schools, community centres and small theatres from the autumn. After a preview, a 12-year-old white boy in the audience excitedly told Halahmy he aspired to play the role of Samir, one of the main characters in the book, who is a refugee. For Halahmy, this demonstrates the power of the play. “There’s a lot of empathy among teenagers and they lose it in young adulthood. It’s about embedding it more deeply,” she says.

Halahmy believes the voting age should be lowered to 16— in her books, the parents are often weak and fallible, while the youngsters are level-headed and resilient.

What next? “I’ve started writing more Jewish characters. Modern, progressive Jews. It’s not so other kids can read about Jews, it’s so that Jewish kids can see themselves in books.”

‘Behind Closed Doors’ is published in the UK by Firefly. Hidden is published by Troika