Time once was that 'holiday reads' were light-spirited romps; something to go well with sun and sangria. These days however, you're every bit as likely, if not more, to find readers of all stripes packing tales of gore, guts and stomach-churning suspense into their carry-on.
Once a crime fiction sub-genre, 'domestic noir' - or 'grip lit' - has moved right to the top of the bestseller charts. Where the likes of Gillian Flynn and Paula Hawkins blazed a trail, countless others are following in their jet stream. Deploying phrases like, 'the next Gone Girl', or 'if you liked The Girl On The Train…', many of the major publishers' are pushing psychological thrillers as their key titles for 2017. Ireland has always punched over its weight on the crime fiction front - think Benjamin Black, John Connolly, Alex Barclay, Liz Nugent and Arlene Hunt - yet psychological thriller writers are enjoying a particularly purple patch.
"It's one of those things in book publishing," observes David O'Callaghan, book category manager at Eason Ireland. "When The Da Vinci Code sold, suddenly publishers went mad for books conspiracy theories. And because of Gone Girl and The Girl On The Train, you'll see that this unreliable narrator trope will be a hot trend that will last until the end of the year.
"There's also a shift from the habitual reader to the person that might only read one or two titles a year. You can't miss these titles - they're sold on a high premise and concept. Don't underestimate the power of a film or TV tie-in, either."
Women are carving out a particular niche in this typically male-dominated genre. "At a glance, it would seem that 75pc of these are by female authors, and while crime has often been thought of as being read by men, I'd wager that 60-70pc of the readership is female," says O'Callaghan.
Of course, the psychological thriller has been around for years. So why the commotion now?
Paula Hawkins has observed in the past that, as a generation of social media enthusiasts, we focus on a sanitized online version of ourselves, while the person underneath the surface is anything but okay. "I think we're all fascinated by the dark secrets that lie at the heart of ostensibly happy relationships," she has said. "There are three key relationships at the heart of The Girl on the Train, and we see them from the points of view both of those involved and of those on the outside, and it is in the contrast between those viewpoints that I think the interest lies."
Female characters - often in crime fiction, found on page one in a pool of blood - have become much more complex in this new strain of domestic noir. Often, they are ordinary women forced into extraordinary situations, and many of them are flawed, conflicted and occasionally unlikeable.
Sheena Kamal is being hailed in the industry as the next Gillian Flynn, and her latest book, Eyes Like Mine, boasts an intriguing protagonist, Nora, with a less-than-perfect past.
"We (women) tend to be put down or held up, and when people are put on a pedestal they will fall," she says. "There's not one person alive who is completely likeable.
"Sometimes the (crime fiction) genre bothers me, the way the dead bodies are often female and the way they're attacked is so gruesome," she observes. "Psychological thrillers make it less about a body and more about a female protagonist who feels these fears in her life."
And this wave of thriller writers, and characters, are making the entire 'women's fiction' landscape shift under our feet.
"What is interesting about 'household noir' is that it seems that the publishing industry is coming around to noticing women more," Kamal adds. "It's not just about romance; it's about stories written by women, not necessarily for women, but that go into the lives and intricacies of women."
When asked about what makes female writers so well-equipped to write psychological thrillers, Kamal adds: "I think they understand the fear better (than men)."
Dublin writer Jane Casey is about to release the seventh title in her Maeve Kerrigan series (Let The Dead Speak), and in it, the acerbic Kerrigan has been made a detective sergeant.
"I've definitely had a lot of evil women and badly-behaved people in my books, but I think it's more interesting to write good people who have done bad things," says Casey. "You think you mightn't do something terrible when forced into a certain position, but these books make you wonder if maybe you might."
With domestic noir hitting fever pitch, Casey has noticed the shift from "the stranger jumping out at you to a situation where suddenly you can't trust the people around you". And modern life has made this more relatable.
"These days, you don't tend to meet people romantically the old way, through people you know," she says. "These days (with online dating) you're taking on a lot of trust and having to accept people at face value."
Bernice Murphy, assistant professor/director of the MPhil in Popular Literature at Trinity College, Dublin, also contends that while domestic noir is very much of its time, female writers have been writing similar books for years.
"Women readers have always been interested in these characters," she says. "People forget that Nora Roberts has written women for years, as has Mary Higgins Clark. Back as far as Daphne du Maurier, there is nothing new about this fiction.
"Crime fiction is a broad term describing anything in which a moral transgression happens, but in this subgenre, you tend to see ordinary people in danger from within an intimate domestic setting, often from the men in their lives," she adds."Since the 80s there's been an openness about domestic violence and abuse. There might be a connection in that, in a US setting, certain women's rights are not as unassailable as people might have hoped," she adds.
"Women are the ones most associated with the home, and many women have conflicted relationships with their own role as mothers and wives. It's no coincidence that a lot of the women writing domestic noir are in their late thirties and early forties. There's a moment in women's history that they're supposed to have benefited from, yet still they find themselves in charge of everything at home."
Of course, any literature dealing with the lives of women has often been denounced as a 'lesser', fluffier, form of writing. Will the psychological thriller, dominated as it is by women writers and characters, befall a similar fate?
"Publishing is largely white male dominated, and if they continue to value people who look like them it just becomes an old boys' club, but I don't think that will be allowed," surmises Kamal. "I don't think it will be considered a 'lesser' subgenre. There has been great support from men across crime fiction, and they themselves are starting to write women into their own procedurals. There's definitely a shift in the right direction."
Big Little Lies By Liane Moriarty
This novel was originally published in 2014, but merits a mention as it's about to be turned into a HBO series starring Reese Witherspoon, Nicole Kidman, Laura Dern and Shailene Woodley. Your next big book club title, in a word.
Good Me Bad Me By Ali Land
(Michael Joseph, €10.99)
Written by a former mental health nurse, Good Me Bad Me has teenager Milly at the heart of the tale; newly renamed and rehomed after reporting her mother's murderous tendencie. Little Deaths By Emma Flint (Macmillan, €14.50) This noirish tale follows Ruth Malone, who discovers her two young children missing from their beds, and finds herself under scrutiny from the media, police and her fellow Queens dwellers.
Here and Gone by Haylen Beck
(Harvill Secker, out 13 July)
Another title mooted as the next psych thriller sensation of 2017 (film rights have been snapped up, predictably), Here and Gone begins on a desolate road in Arizona where Audra is fleeing her abusive husband in the family car with her two young children.
Skin Deep by Liz Nugent
(Penguin Ireland, out 22 August)
The Unravelling Oliver author returns later this year with a sinister new read: this time about a woman living in the Cote D'Azur, posing as an English heiress, who finds herself down on her luck.
The Grown Up by Gillian Flynn
(Weidenfeld & Nicholson, out November 3)
Arguably one of the most anticipated titles of the year, The Grown Up sees Flynn's sleight of hand in full flight. It revolves around Susan, a lonely rich woman, Miles, her stepson and an unnamed narrator.