Melbourne-born, Canberra-educated and now based in Sydney’s eastern suburbs, Nix has sold more than 6 million books worldwide, according to publisher Allen & Unwin. His fantasy and science fiction books for children and adults have been translated into more than 40 languages. The 56-year-old says he is mostly spared the “ludicrous” online criticism from men who argue women cannot be knights in a medieval fantasy. “I actually don’t get them very often, but women authors do,” he says. “Which again is a male privilege thing. If a woman had written the same books I did, they would have copped much more flak about gender equality.” Nix says other contemporary issues also “creep” into his novels - the books in his Old Kingdom series as well as Angel Mage are concerned with the plight of refugees and “the blaming of others for what is seen as their faults”. “You can address things allegorically,” he says. “Whatever you write, it will be infused with things you’re concerned about.” Nix also expresses an interest in reversing stereotypes in his novels “or just subverting readers’ expectations”. His 2017 book, Frogkisser!, which is being developed into a movie, twists the traditional frog-prince fairytale into a story of a feisty princess who can break curses with magic kisses.

“Their plan is to make an animated musical,” Nix says of the film production. “Whether it will be made, who knows?” Nix’s Keys to the Kingdom series is also set to be adapted for the big screen, but the author has learnt from past experience not to count on Hollywood. He co-wrote a pilot based on the Old Kingdom books for Amazon which, he says, “loved it up until the moment they decided not to pick it up”. It was previously pitched as a feature film to Brad Pitt’s Plan B production company, he says. “Curiously, back in 2009, the studio’s biggest problem with Sabriel was it had a female protagonist. In fact, we kept getting asked ‘When’s the guy coming in?’.” Garth Nix (left) was appointed an ambassador of the National Library of Australia last year as part of its 50th anniversary celebrations. Credit:Jamila Toderas Above a branch of the Commonwealth Bank in Sydney’s eastern suburbs, Nix’s office is a hive of creativity. His neighbours include film director Kim Mordaunt and producer Sylvia Wilczynski, whose last movie was the award-winning The Rocket, documentary producer Kelly Stoner and whale photographer Jem Cresswell. His workspace is filled with towers of books he has authored as well as a standing desk from where he conjures fantasy worlds at the impressive rate of a book each year.

Nix became a full-time writer in 2001 after a career in publishing including as a literary agent, book editor, marketing consultant and bookseller. He signed up Liane Moriarty's sister, Jaclyn, and sold her first novel, Feeling Sorry for Celia, a week after finding it in a pile of unsolicited manuscripts. He studied writing at the University of Canberra and was a part-time soldier in the Australian Army reserve for four years. “We mostly made things and blew them up,” he says. “We built bridges and placements, and demolitions was a big part of it.” He was also one of the authors chosen to be an ambassador to commemorate the 50th anniversary of the National Library of Australia last year. Nix acknowledges the praise politicians lavish on cultural institutions such as the library, but “they’ve got to give them the money". “As is so common with politicians, they say one thing and do another,” he says.

He will appear at the library on December 12 with fellow screenwriter Felicity Packard, one of the creators and writers of true-crime drama franchise Underbelly as well as a contributor to television dramas such as Janet King, G.P. and Blue Heelers. Loading Nix is modest about his success as a writer, attributing a significant part of it to luck. “A lot of that is just about what’s going on with the zeitgeist,” he says. “You can write a wonderful, wonderful book but it’s just at the wrong time. It can be too early or too late or it can be badly published. There’s so many things that can not work.” He says publishing and bookselling is about the “transfer of enthusiasm” from one person to another: “Word of mouth is still the most powerful tool.” An avid reader since childhood, Nix confesses to a “particular love” for fantasy and science fiction. “It’s the ability to draw your own boundaries and create things within it,” he says. “You do have a great scope to make stuff up. Even though to make it work, it does have to be connected to reality.”