“Honestly, a little crime novel set in rural Quebec by a middle-aged woman? That did not have ‘bestseller’ written all over it,” Louise Penny says with a laugh. “It had ‘big fat failure’ written all over it.”

She adds, with a shake of her head: “I sit here astonished.”

Penny’s wonderment, of course, is because her books – the beloved Inspector Gamache series – are bestsellers many times over, both here in Canada and abroad. In fact, the week that we speak, the 18th instalment, A World of Curiosities, has debuted at No. 1 in The Globe and Mail’s fiction chart – selling enough copies to make it the biggest launch of a Canadian hardback since Margaret Atwood’s The Testaments. This is all around the same time that a Prime Video adaptation of the series, Three Pines, is rolling out episodes to great fanfare.

Penny was an executive producer on the show, but notes wryly that the “meaningful consultation” agreed to in her contract was, in practice, “essentially meaningless.” There are parts of the adaptation she loves – the casting of Alfred Molina as the titular chief inspector, Gamache, and the introduction of a B-plot around missing and murdered Indigenous women – but there are also decisions that she’ll candidly tell you were disappointing, even upsetting.

“I don’t want readers to think that I’m okey-dokey with everything when obviously it’s not as I would have liked,” Penny says on a video call from her home office, the snow-dusted evergreens of Knowlton, Que. – the village that inspired her books’ setting, Three Pines – visible behind her.

“They made the decision to focus on the plot, and the cops, and not so much on Three Pines. The villagers are pretty much furniture,” she says, pointing to a particular line in the script that describes the fictional hamlet as a place where “if you don’t belong, it’ll toss you out,” to paraphrase slightly.

“That’s the opposite of what Three Pines is.” She refers to her own adopted village as an inclusive sanctuary that she only found after years of searching for home elsewhere.

Penny spoke with the Globe and Mail about the series’s success, when it might come to an end and why she most certainly is not a “cozy mystery” writer.

At this point in your career, what does being No. 1 on the bestseller list mean to you?

To hit the top of the bestseller’s list is never a given, and it’s always a struggle. I’m always aware of the fact that it’s not just me – it’s the whole team, so it’s a celebration for all of us. And dear God almighty, what a shame it would be if I didn’t appreciate it! I’m living not only my dream, but most people’s dream.

Can you remember the first time you made the bestseller list?

The first time was hysterical. I was on tour, and my publicist, Sarah Melnyk, and I ran into this little booth in the hotel when the publisher called, and I’ll never forget when he said: “You’re No. 1.” I remember looking at Sarah and just starting to cry, because you never think you’ll hear those words.

This happened quite a few books into your career. Was there a disappointment every time before then when you didn’t make the bestseller list?

The problem is setting ourselves up with expectations that this will be the breakout, I’ll be the new Girl With The Dragon Tattoo or whatever, and then it doesn’t happen. I’ve gotten much better at taking a step back. For me, the matrix now is building, seeing the numbers go up, seeing more and more people reading the books. That is meaningful.

There is a really interesting conversation emerging about our obsession with murders, such as those endless podcasts that dive into all the grisly details. Have you ever thought that you started with a certain perspective on how we talk about murder, and now 18 books in, you’ve had a chance to re-evaluate?

I haven’t changed in my approach to the crime. Gamache says early on, and it’s a thread through the whole series, that crime is emotion gone rancid. In order to find the perpetrator, he has to follow the trail of slime to the personality that is twisted. The crimes I talk about are not spur of the moment – they started years and years ago, and they should never be trivialized.

Perhaps because Gamache isn’t an anti-hero, but a decent, lovely human being, there is a confusion that you write “cozy mysteries.”

When I’ve heard “Gamache is Poirot or Murder She Wrote set here,” it makes me think they couldn’t possibly have read my books. These are psychological thrillers. They don’t have blood, but they’re about the marrow. And what is more terrifying than what we hold deep down, and what comes bubbling out? I’m shocked that after all this time, you could read A World of Curiosity, which is about darkness and blind spots and the non-limits of evil, and still think that’s cozy. That is facile, and it’s simply not true.

Have your readers shaped your writing at all?

I’m on my train, and you’re welcome on it, but the train has left the station. You need to trust me. Nobody loves these characters or knows them better or respects them more than I do. Read them or not, because I’m loving writing them. I do put little Easter eggs in every now and then or some slight references, as a shoutout and a thank you to people who have read the whole series, but they’re not pivotal to the plot.

Are you ever surprised about who reads your books?

It’s no surprise that women of a certain age make up the bulk of my readership, and I’m grateful for it. But I don’t think it’s a demographic, it’s a mindset. It’s anyone who is curious, who sees the value of kindness, and doesn’t see “nice” as a pejorative but as a goal. It’s those who believe in goodness, and understand that goodness often comes out of being shattered. The books are about terror, but at the end of the day, they’re about forgiveness.

You talked about being on a train with this series. Does it have a terminus, or is this going on into infinity?

Until it derails, and I die in the crash, the train is going forever. I don’t understand why an author would kill off their main character. Even if people stop reading, I’m still on the train because I love it. Honestly, to sit here in my little house in the country in front of the fireplace with a mug of coffee, and write – how joyous is that? How lucky is that? And if no one reads them anymore, so be it. I’m still happy.