Paula Hawkins stopped by Ali Velshi’s MSNBC show to discuss her novel The Girl on the Train.

Hawkins’ novel, published by Riverhead in 2015, follows Rachel Watson, a divorced, alcoholic woman who becomes obsessed with a couple she sees during her daily commute on a train; she’s then enmeshed in an investigation after one of them goes missing. In a starred review, a critic for Kirkus wrote of the novel (which was adapted into a 2016 film starring Emily Blunt and Rebecca Ferguson), “Even the most astute readers will be in for a shock as Hawkins slowly unspools the facts, exposing the harsh realities of love and obsession’s inescapable links to violence.”

Velshi asked Hawkins about the theme of alcoholism in the novel.

“I was specifically interested in the thing where someone drinks to the point where they can’t remember what they did the night before, and the fact that that divorces the person from a proportionate sense of guilt and responsibility for what they’ve done,” Hawkins said. “That was the thing I found really intriguing, so I wanted to dig into that a bit.”

Velshi praised Hawkins’ use of an unreliable narrator in the novel, and asked why she thinks it works in the book.

“The thing about Rachel is that she’s unreliable in quite a specific way, because she’s not even reliable to herself,” Hawkins said. “She literally doesn’t know what time she came home, whether she called someone, what she said to them. So her unreliability, it’s not one of those situations where she’s deliberately lying or deliberately trying to mislead somebody.”

Michael Schaub is a contributing writer.