As implied above, this was a good example of an enjoyable sub-genre which can all too easily fall into the world of lurid cliché and historical poverty porn. The fact that it was based on a Peter Ackroyd book probably helped - certainly the intriguing plotting and structure. I also liked the subtle and understated gay subtext re the lead (Bill Nighy) and his constable assistant. Nothing made of it but the existence of their similarity was just quietly acknowledged.
the look of the piece was characteristically good and the scenes in the music hall featuring Dan Leno (a central character) were particularly evocative. An appearance by Karl Marx was also—-intriguing. I intially thought that it was a bit excessive but given the precise time and date of the events, it was certainly authentic - and as the British library played a signifcant role, this made it even more so.
The ending was powerful and very effective with a nicely ambiguous touch as to exactly who had succeeded in their aims and how. An enjoyable and effectively lean 90 minutes.