Author Kristel Thornell returns to her Blue Mountains childhood in latest novel, The Sirens Sing

The acclaimed writer describes the new work - released on September 7 - as a "love letter to those places and time".

The Sirens Sing is partly the story of two Blue Mountain teenagers drawn together by their study of Italian. David is smitten with Heather, but has no idea how she feels about him. Besides Italian in common, they are both children of struggling single mothers. At a festive evening to celebrate Heather's final high-school exam, events take a course that will profoundly change the lives of everyone present.

Thornell, who lived in Blackheath from ages eight to 18 ("It's the place where I've lived for the longest stretch of time"), created the novel's world entirely from her childhood memories.

"I really wanted to do it through the lens of nostalgia if you like. I wanted it to just be the strength of memories and reconstruct as much as I could through what had stayed with me," she said.

"It's amazing how close it all felt when I started to recreate that world. It felt incredibly immediate to me."

It's likely to feel incredibly immediate to readers as well, especially those who grew up in the Blue Mountains in the same period.

The Sirens Sing is filled with local references - from descriptions of the swimmers at Blackheath Pool, to high school house parties, to the frustration of waiting for replacement buses when the trains are out of action.

While Thornell's two previous novels were also set in real historical periods, she "hadn't come this close to home before" in any of her work.

"The time and the distance [away from the Blue Mountains] made me want to go back. It probably made me nostalgic and want to write a love letter to those places and time," she said.

Thornell went to Blackheath Public School and started her secondary education at Lithgow High School before switching to Korowal School in year 8.

Like Heather, the main character in The Sirens Sing, she was an only child with a passion for languages who was "quite solitary and very bookish".

"I think with any fiction you're always mixing bits of yourself into your characters even when they seem to be far away from you," Thornell said of the semi-autobiographical elements of the The Sirens Sing. "This one certainly comes closer to the kinds of social worlds I grew up in... There's a lot of me, and lot of the people I know, mixed into the different characters."

While it's partly set in the Blue Mountains, The Sirens Sing was written over three years in Rome, Italy (where Thornell enjoyed an Australia Council residency) and her home in Marseille, France. The novel was finished during France's COVID-19 lockdown, which the writer described as "pretty intense".

"You could only go one kilometre from your home when you went out on a walk. You had to leave the house with a signed letter stating the purpose of the outing and the time and everything. It was almost like you were carrying your papers in wartime," she said.

But there were upsides to France's long lockdown as well.

"I was lucky because I live quite near the sea... so I trained myself to swim all winter even when it was really cold. That was a nice aspect of the lockdown."

This new interest has bled into the novel she is currently working on, which is set in Marseille and "has a lot of sea swimming in it". Its central character is a translator - a role Thornell has also given herself by planning to write the French-language version of the work as well.

But right now she is looking forward to returning to Australia to promote The Sirens Sing and to discover the reaction to her latest work

"It's exciting when you get sent copies of the book and you see that it's suddenly a physical object... You've had this whole world inside you that's been private for so long and then suddenly it's out and you can share it."