Georges Simenon was working on Maigret, Dorothy L Sayers dreamt up Harriet Vane and Agatha Christie wrote her first Miss Marple novel. Why was this such a bumper year for crime fiction?
‘Anyone who murdered Colonel Protheroe,’ declared the parson, brandishing a carving knife above a joint of roast beef, ‘would be doing the world at large a favour!’ It was a careless remark for a man of the cloth. And one which was to come bac