Off the shelf:
James Runcie

Since Edgar Allan Poe’s Murders in the Rue Morgue (Penguin Classics, £5.99), the art of mystery writing has evolved from whodunnits and howdunnits to whydunnits. Perhaps this says something about the evolution of modern society, the need for a psychological explanation for desperate and violent acts. When I started to write The Grantchester Mysteries, I saw them as moral fables that would explore how hard it is to forgive those who would do us evil, how easy it is to be tempted into revenge, how difficult it is to lead a good life and what justice really means. My go-to book was Dostoevsky’s Crime and Punishment (Wordsworth Classics, £1.99), the story of Raskolnikov, a young, desperate and impoverished student who murders a money-lender in the deranged belief that he is somehow entitled to do so. Crime, he convinces himself, is permissible if it serves a higher purpose. This appallingly misconceived rationalisation of a crime that then goes wrong provokes a fit of conscience that drives him to the point of insanity: a madness that is only redeemed, in part, by love.

My friend John Mortimer once told me how easy it was to slip into crime and how amazed he was that there weren’t “more out and out bastards in the world”. James M Cain’s 1935 novel Double Indemnity (Orion, £8.99), about an insurance salesman tempted into murder by a duplicitous housewife, is a masterpiece of economic storytelling in which the reader is as seduced as the poor sap who takes the rap. “How could I have known that murder can sometimes smell like honeysuckle?” he complains in Billy Wilder’s masterful film version.

Sometimes a brilliant idea is all it takes. Patricia Highsmith’s Strangers on a Train (Vintage, £8.99) explores the ingenious device of two men committing murders on behalf of each other, so both have alibis and there is no apparent motive. It’s the belief that they can get away with it that allows them to divest themselves of any moral imagination; but the supposedly infallible cleverness that convinces a man to become a criminal (see also Highsmith’s Ripley series) is undermined by the fact that both author and reader are eventually even cleverer than they are. This is the satisfaction crime fiction provides: we travel into the dreadful heart of human possibility, look into the heart of darkness and then, most of the time, we see justice restored.

But it can be a painful process (whoever thought this was “entertainment”?) and it can sometimes be more difficult for characters to stay with the angels rather than stray with the devil. On my shelf now are three books that raise moral issues in a compulsive manner: When Good Men Do Nothing (Kindle, £2.32), by Paul Grzegorzek, The Chalk Circle Man (Vintage, £8.99) by Fred Vargas and How The Light Gets In (Spere, £8.99) by Louise Penny. I’m looking forward to getting to grips with all of them in the hope that they will make me a better writer, a better reader and, who knows, perhaps even a better person as well?

Sidney Chambers and the Forgiveness of Sins (Bloomsbury, £7.99 / Audible, £21.39) is out now. Sidney Chambers and the Dangers of Temptation (Bloomsbury, £14.99) is out on 2 June