My son John, dedicated flâneur, connoisseur of city scenes, writes from London—where he works, and commutes—that Underground smells of ozone and Overground smells of piss. Which brings to mind all manner of things about the Brooklyn I grew up in, from the smell of a low tide to the smell of my parents’ bed.

To the funky smell of library books, a mix of bindery paste and other people’s food, and toilets, and the way this smell coloured one’s reading. The Five Chinese Brothers was creepy enough to begin with, without the smell and the weird stains of the library copy I borrowed again and again.

Disgust is an underrated avenue to enlightenment, as my father perhaps wished to convey in his rule that one should never pick up a newspaper lying on the street or on a bench, because you never knew what might be underneath it.

Revulsion certainly accompanies one these days. You wake up with it and go to bed with it. Like wood ash or cooking grease or that emulsion of diesel fumes and incinerator waste that coated the venetian blinds and defied even the heroic measures of spring cleaning.

I am reading just now a work by the Icelandic writer Yrsa Sigurðardóttir, Ashes to Dust, the third crime novel featuring her lawyer-heroine Thóra. The title alludes to an originative event, the eruption many years earlier of a volcano that buried a remote island town in lava and ash. Burying with it as well secrets of violence, murder, revenge, complicity and guilt, secrets only now revealed in their horrible consequences.

A deft alignment of symbol or figure—the smothering ash—with a patent moral about accountability. And about facts. A thing in itself suiting the mood of the hour.

But reading this enjoyable and workmanlike example of genre fiction I notice something else too. Like many works of its kind, Ashes to Dust begins with a gruesome scene, a torture and murder as it is being experienced by the victim. Nothing is spared and nothing is explained. No motive, no reason. Eventually we will get there but not now, and anyway these are not really very important. What is important is that we are pitched headlong into the story. Propelled by pity and terror. We want merely to be released, to come to the end.

Novice writers of fiction are encouraged to avoid the plot-driven—as opposed to the character-driven—but plot-drivenness is not so much a drawback of genre fiction as it is its distinguishing feature. It is how these works do what they do, and what that is is important and valuable as a form of moral instruction, in which disgust is the portal and plot is the path of resolution and return. Which was the point of The Five Chinese Brothers. And of finding oneself (John again) on the bridge over the tracks at Highbury & Islington station.

Could it be that Scandinavian noir holds a key to surviving the next little while in sanity? Forget reasons. Be guided by disgust. The dodgy smells and dubious stains. Wait on plot. Come home safely.