Lightning Men by Thomas Mullen (Little Brown, £14.99) is the second volume of one of the most remarkable and timely series crime fiction currently has to offer.
It's set in the strictly segregated city of Atlanta, Georgia, in 1950 where the economics of post-war capitalism mean that the border between white and black areas is constantly disputed, creating a front line where big profits can be made by realtors happy to put private gain ahead of public ideology.
Violence is inevitable as fascist factions vie for power and middle-class blacks buy houses in areas reserved for whites.
The almost powerless "negro police" who patrol these streets must contend not only with nazis, Klansmen and turf wars between black criminal gangs but, above all, with the white colleagues who despise and terrorise them.
Mullen's success in making a hugely enjoyable thriller from these ingredients, without ever minimising the horrors he's writing about, is truly impressive.
Another period of rapid change, after the first world war this time, is the backdrop for Death In the Stars by Frances Brody (Piatkus, £8.99), in which Yorkshire private investigator Kate Shackleton attends a party to witness the 1927 total solar eclipse. She's been invited by a music-hall star, who's convinced something bad is going to happen and, sure enough, it's not long before a body is discovered.
This is essentially an old-fashioned, good-fun murder mystery, making excellent use of its setting in variety theatre's fading years.
But there's also a vein of melancholy, inescapable in any novel dealing with those generations whose every thought, deed or memory was haunted by the lasting pain of the Great War.
Former LAPD murder detective Harry Bosch is now retired and working as a volunteer for the police department in San Fernando, a small town completely surrounded by Los Angeles, in Michael Connelly's Two Kinds of Truth (Orion, £19.99).
As the permanent recession continues, and police budgets shrink, Harry's part-time help looking into cold cases is invaluable. But it's a case he solved three decades earlier that's keeping him awake at nights now.
The murderer of a young woman has had his conviction examined by a miscarriages of justice unit and they've found forensic evidence which might clear him.
But Harry knows he got the right man and must somehow find out how the killer has foiled a seemingly unimpeachable system — or else see a sadistic misogynist set free, while Harry's own reputation for integrity is destroyed.
The central mystery, a kind of locked-room puzzle, is elegantly solved at the end of a gripping and eventful story.
Who benefits financially when xenophobic panic seizes a nation? That's the question Sergeant Campbell Lawless must ponder in Lawless and the House Of Electricity by William Sutton (Titan, £7.99) as a series of terrorist attacks in 1860s Britain is blamed on immigrant extremists.
This is another winning entry in another extraordinary series, with Sutton delivering a rich stew of satire, social history and adventure.