If you’re familiar with even just one of Ruth Ware’s edge-of-your-seat thrillers (The Woman in Cabin 10, anyone?), it will come as no surprise that her latest is just as enthralling. Told from the perspectives of two young women, One by One begins with the team at a multimillion-dollar tech start-up heading to a ski chalet to discuss the future of the company. Sounds peachy – until an avalanche hits, a guest disappears and, to paraphrase Ware, the heat gets turned up despite the snowy scene. “What makes a book fun to read, particularly a crime book, is putting people in difficult situations and creating conflict – it’s that conflict that makes a plot fly on the page and makes you want to read on,” says Ware. “That’s certainly what I did with my characters in this book: I put them in a tepid bath and then turned up the heat.”

How did you come up with the idea for this story?

“I love closed-room mysteries, and for a while I wanted to do something classic where people get picked off. The body count tends to be quite low in my books, and often the murder takes place completely offstage and you don’t see anything at all. So it was fun to experiment with a more classic crime structure where there’s a higher body count.”

What research did you have to do?

“The skiing side of it was easy – I really enjoy skiing and I’ve stayed in chalets (though not as luxurious as the one in the book) – and I had been a server so it was easy to put myself in the shoes of a twentysomething woman trying to organize this disparate party. But the start-up culture and the app were way outside my comfort zone and experience. I think there is something really particular about that exponential growth when you’ve gone from being a kid with a good idea to suddenly being handed wads of money. It’s not like it was at the height of the dot-com movement, but it is still possible to be an amateur enthusiast one day and then be running a multi-person multimillion-dollar company within a comparatively short space of time. And the kind of head change that requires and the fact that the entrepreneurial skills that got you to be a start-up are not necessarily the same skills that will equip you to run a multi-national company. It was fun to think about and research.”

Did you know the ending when you started writing?

“Yes, I did. I think you need to play fair with the reader and give them sufficient chance to solve the mystery. And you can’t do that if you don’t know. I almost always know – not all the details, but I know who did it and how they did it, and the ‘why’ is something that becomes apparent. I love a small cast of characters. I think it makes for a really elegant puzzle. What’s really unsatisfying for me in a crime novel is getting to the end and the author introduces some person from page two that you haven’t seen since and expects you to remember that they have a motive. It can just be a bit random. With limited characters it’s a more satisfying puzzle because as a writer you have to work much harder to misdirect the reader since they naturally have a limited menu of options.”

Psst! You can buy One by One here!