One Good Turn by Kate Atkinson

It is summer, it is the Edinburgh Festival. People queuing for a lunchtime show witness a road-rage incident – a near-homicidal attack which changes the lives of everyone involved. Jackson Brodie, ex-army, ex-police, ex-private detective, is also an innocent bystander – until he becomes a murder suspect. As the body count mounts, each member of the teeming Dickensian cast’s story contains a kernel of the next, like a set of nesting Russian dolls. They are all looking for love or money or redemption or escape: but what each actually discovers is their own true self.