Murder and mind games with rhyme and reason

“The interweaving of alternate chapters, from the police point of view and the heroine’s point of view, is similar to poetry because you’re balancing the narrative out,” she says. “Just as if the first verse of a poem had an ABAB rhyming scheme, then you’d expect the second verse to have an ABAB scheme. It’s like setting up a pattern and then following it, and having two elements which are working together but also straining away from each other makes it quite taut. So there are similar considerations at play as would be if I was writing a poem.”

If Hannah is proudly old-fashioned in her love of poetry, she’s similarly happy to name-check Agatha Christie as a strong influence on her crime writing. The Carrier, which opens with a murderer declaring his guilt, has strong echoes of the type of mystery beloved of Christie and her fellow authors of the golden age of pre-second World War crime writing.

Thinking inside the box

“I do like that kind of locked-room mystery,” she says. “One reason is that you’re putting a boundary or a constraint in place, which it makes it all more intriguing. The tighter you box yourself into a corner [as a writer], the more impressive it is if you can produce a solution to it all.

“But it really isn’t so much about who did it as why. The person who killed Francine – that could have been anyone, but what matters is why the person killed her. And ultimately, the question becomes who’s responsible for her death. What I was aiming for was for the reader to quickly realise who did it, but also realise that that is a different question from who is guilty of the murder.

“The person who actually committed the murder, given the context in which it was committed, maybe isn’t the most guilty person involved.”

Hannah’s characters, whether cop or villain, are invariably morally compromised. “Seriously, are there really any ‘goodies’ or ‘baddies’ in real life, or is everyone just a bit flawed and dodgy, and struggling on as best they can? That’s the same question that comes up in all my books. I don’t believe in goodies and baddies.

“The murderers in my books are not the baddies, just the people who, among the general crowd of screwed-up people, are the ones who were pushed furthest.

“I think the conventional crime novel is the battle between good and evil in the form of detective and murderer, or protagonist and murderer,” she says. “In my books, the battle between good and evil is there, but it’s within every person. And to win that battle isn’t so much down to being good all the time, it’s to realise there’s no such thing as guilt or innocence. That we’re all implicated.”

Sophie Hannah’s The Carrier is published by Hodder & Stoughton