This is a long book (650 pages!), with lots of politics thrown into the mix to add to the central mystery. The novel could have used some editing, but publishers don’t edit much these days — and who’s going to tell J.K. Rowling to shorten her prose by 30%? If she had done that, this could have been an excellent book, but it’s still a very good book for retirees and other readers who have sufficient time on their hands. You don’t have to have read the first three novels in the series, but I’m sure it helped that I had done so. Familiarity with the main characters and their back stories makes it easier to keep track of what’s going on. If you’re late to the party, you may wonder about Cormoran Strike’s unusual first name, but that’s because your familiarity with Cornwall probably begins and ends with The Pirates of Penzance. Anyway, no knowledge of Cornish history or linguistics is necessary in order to enjoy this book; all such knowledge would do is satisfy your curiosity about that name. Also, if you’re new to Robert Galbraith, be forewarned that there are no wizards, goblins, or magicians in the series: it’s all muggles, all the way.
Aside from the politics, Lethal White is a well-told, intricate mystery with a lot of tension between characters. As one review pointed out, the lead characters’ relationship seems to have been inspired by the television show Moonlighting, but I don’t know how meaningful that comparison is to most of today’s readers. Despite the length of the story, it kept my attention the entire time. You’ll be sick of Matthew long before the end, and there are plenty of other obnoxious characters ranging from conservatives to socialists; interpersonal relationships are central to the narrative, and those obnoxious characters are balanced out by Strike, Robin, and quite a number of supporting cast members. Read it!