Bookish, a 6-part tightly edited but still not interesting enough, series is leaden with atmospheric tension. This is London in 1946; the Depression hangs dangerously in the air. There are long queues at food ships which two detectives insouciantly break while in the line of duty.

But the focus of the labyrinthian plot is a bookshop owner eponymously named Gabriel Book (imagine if he was a criminal he could named Gabriel Crook, or a chef Gabriel Cook). Mr Book (played with a mischievous wisdom by Mark Gatiss) seems more interested in young boys than books, which is not so okay back in those times.

When we first meet Gabriel Book he has just recruited the rakish Jack (Connor Finch) as an assistant in his bookshop. Gabriel’s interest in Jack seems more than cursory, though he pretends otherwise.

Gatiss who has also co-written this intriguing failure, is adept at bringing out the onion-like layers in Gabriel Book’s character, especially his relationship with his wife Trottie (Polly Walker). Book loves his wife, they cuddle up in bed, but they sleep apart.

All this is purely in the realm of conjecture in a series that revels in innuendos. A fog of crypticism envelops the plot as Gabriel Book solves three murder mysteries, one more abstruse and dull than the other.

Not that the presentation is entirely denuded of interest. But the prevalent mood is lacklustre and self-important. The actors are keen enough to make themselves believable in the era they represent. But they don’t seem to go anywhere beyond the skin of their characters. The emotional underlayers are lost in a blizzard of haziness.

I had very little interest in the mysteries that were slithering into solutions, and almost zero patience waiting for them to be solved. Adding to the mood of fogginess is the nocturnal mood. Most of the shooting is done in the night light, adding to the feeling that we are being taken on a ride. Albeit in a stately stagecoach.