It turns out having a relatively new baby and reading a 963-page post-apocalyptic vampire novel - quite small print, too - in five days wasn't much of an achievement after all.
Justin Cronin, the writer of the vampire trilogy The Passage, The Twelve and, now, City of Mirrors, says he gets a fair amount of feedback, mainly via social media, from new parents saying they devoured each of the books in days.
"Oh no, you're not alone," says Cronin, talking from a hotel in Norwich, where he's winding up a British publicity tour. "I hear from a lot of new parents who said they read the books quickly and enjoyed them. I also get quite a bit of feedback from people in the military and those incarcerated with time on their hands ... "
He says the feedback is warm and supportive and that he's a fan of readers being able to contact authors via social media. He recalls the days when the only way of communicating with an admired author was by letter or at a book signing.
"It was hit and miss whether they responded to a letter; there was little chance to talk at a signing so I think it's great that people get in touch and I do try to respond to each one although I've got a little behind lately."
He may fall farther behind on that correspondence. Based in the US, Cronin tours New Zealand in September and is speaking at events in Auckland, Wellington, Dunedin and Christchurch. It will follow a similar promotional tour of Australia.
"Whenever those polls come out about the best places to live or quality of life, it's usually the Scandinavian countries, Australia and New Zealand that seem to be at top so I'm quite excited to see it for myself," he says. "Australia also figures in my books and I chose it as homage to the great apocalyptic novel, On the Beach - and maybe I put it in so, one day, I could go there."
Is he surprised the books have done so well here? Self-deprecating with a boyish laugh, Cronin says he's surprised when anyone tells him they're a fan of his books.
After all, they're not your typical vampire tales. It's fair to say they're long and intricate and, for a world supposedly sparsely populated after a government experiment gone drastically wrong, feature many, many characters in different time periods and locations.
That they appeal to parents isn't a shock, given they're so much about parents and children and the world being bequeathed to future generations. There's rigorous plot and character development, but also the rip-roaring and visceral action of, well, a novel about vampires.
"It arose from the story-telling impulse that you should write about what you care about locally and globally," Cronin says. "So there's a lot about parents and children because I'm a parent and I expanded out [the story] from there.
"The story grew to encompass cultural, philosophical and spiritual concerns and it changed along with my own circumstances. It's basically all about what's been on mind at a phase in life when you're not waiting for things to start because they're here; you've got the job and the house and the family and you're trying to keep it all together - to survive - and then those concerns are slightly less pressing so you start to think about what it actually means to be a human being."
He acknowledges the legend of how they came to be is true: a creative writing tutor and professor of English, Cronin had written a couple of literary novels and won the United States' Hemingway Foundation/PEN Award and a Whiting Award for his troubles.
He was taking time out to help look after his two children while his wife worked and, on after-school bike rides around the neighbourhood, his daughter, Iris, started suggesting ideas for a story where a girl was the heroine.
"I had no intention of writing it because, well, you can't let an 8-year-old tell you what to do with your career!"
But when father and daughter sat down and batted a few ideas around, Cronin decided what they had was the kernel of a good idea. He spent a lot of time building a foundation, plotting out the entire first novel and drawing up extensive treatments for the second and third books.
There were, of course, no guarantees The Passage would be successful but it got a ringing endorsement from master author Stephen King and debuted at #3 on the New York Times best-seller list.
Cronin says it's been a mad few years and he thinks, more than ever, that writing is a crazy way to earn a living; working in relative solitude and then sending stories out into a world where whatever is going to happen happens.
Although it took two years between The Passage and The Twelve, City of Mirrors has been a longer time coming. Cronin was diagnosed with cancer - thankfully treatable - and had to devote time to recovery.
"Of course something like that changes your outlook - there are all sorts of cliches about that - but, for me, I wanted to ensure the last book was as absolutely right as I could make it."
From the beginning, he's had the ending figured out because there was no way he wanted to start a book then face the prospect of having to wrap it all up without any real plan.
"I always had a place I wanted to go, right from the beginning."
So now what? Cronin reckons it's time for a holiday and to take a breath, to take stock and to consider that question anew: what does it mean to be human?
CITY OF MIRRORS
by Justin Cronin