'Troubled Blood' is Robert Galbraith's most ambitious Cormoran Strike novel, clocking in at over 900 pages as it weaves together a contemporary missing person case with a 40-year-old cold case. The book follows private detectives Strike and Robin Ellacott investigating the 1974 disappearance of GP Margot Bamborough, while simultaneously dealing with personal upheavals in their own lives.

This is quintessentially for readers who love procedural mysteries with deep character development and aren't intimidated by length. Galbraith excels at creating a lived-in world where the detective work feels authentic—countless interviews, dead ends, and painstaking evidence review.

The relationship between Strike and Robin continues to evolve compellingly, with Robin's growing confidence as an investigator and their complex personal dynamic driving much of the emotional weight. The historical mystery is well-researched and atmospheric, capturing 1970s London effectively.

However, the book's greatest strength—its thoroughness—is also its weakness. At nearly 1000 pages, the pacing drags considerably in the middle sections, with repetitive interview sequences and tangential subplots that could have been trimmed. Some readers may find the resolution somewhat anticlimactic given the extensive buildup. The book also sparked controversy for its portrayal of a cross-dressing suspect, which some critics found problematic in its handling of gender identity themes. Fans of the series will appreciate the character development and won't mind the length, but newcomers should start with earlier, tighter entries like 'The Cuckoo's Calling.' Those seeking fast-paced thrillers should look elsewhere, but readers who enjoy immersive, character-driven procedurals with literary ambitions will find much to appreciate. The book works best for patient mystery lovers who view the journey as important as the destination.