Lethal White will be the fourth book in the Cormoran Strike series by this author, aka J K Rowling. I read and enjoyed the first three novels, The Cuckoo’s Calling, The Silkworm and Career of Evil. My favorite was the first one though. Strike is an appealing character with his handicap and imperfections; Robin is the perfect foil for him. The books have recently been made into a TV series although I have not seen it. I just pre-ordered the new book and am very excited about it. I highly recommend putting it on your TBR pile if you enjoy mystery/suspense reads.
By the way, you probably all know this but Rowling published under a pseudonym wanting the books to be judged on their own merit. She was outed though.