If you adored Shadow of the Wind, this novel will not disappoint. If you're new to the series, welcome. I'm jealous of the first time reading experience you're about to have. One of the wonderful things about these books (this is the 4th and supposedly final) is that they can be read in any order and while they're all standalone stories, each adds a layer of context and insight into the others. It is truly a labyrinth of storytelling and masterfully done. Having said that, knowing the first three books added to my experience reading The Labyrinth of the Spirits. It's not mandatory to begin with The Shadow of the Wind, but I would recommend it.Atmosphere abounds in this genre-defying book. I felt like I was right there with the characters, twisting through the streets of Barcelona, hiding in the shadows, breathing in gunpowder, living off of caffeine and adrenaline, and pushing through too-little sleep to uncover the next piece of the puzzle. The Semperes and Fermin Romero de Torres return, as do other friends and enemies from the previous books, but the main protagonist in this story is Alicia Gris, a bold and alluring woman assigned to investigate a missing person (a returning character who I'll let you discover). The pacing is fantastic. It starts with short snippets into various POVs and story lines as a sort of appetizer before slowly building on the main mystery of the book. You gradually uncover more as the plot builds and you delve deeper into the heart of the city and characters. About halfway through the pieces begin to fall together with increasing speed and for the next 200 pages or so it's non-stop, unputdownable thrills. Yes, there are a few twists, one of which actually made me close my book in disbelief for several minutes before I felt capable of continuing. Nothing felt contrived. Everything felt fitting. I didn't feel cheated or misled. The pace slows down again at the end of the book to ease you back to normal and fill in the gaps. In the end you also get quite a bit of insight into what Ruiz Zafon values in the craftsmanship of writing, which is woven in along with acknowledgments of sorts in a clever way that not everyone may not love, but I quite enjoyed. It is one satisfying, gorgeous read.Like the other books in the series this installment is a wonderful mix of genres: mystery, historical fiction, police procedural, political thriller, romance, fantasy... If you're looking for a fun, light mystery this isn't for you. It's over 800 pages, with multiple characters and sub-plots to keep track of, and, while not gratuitous, it has some torture and squeamish bits to make you uncomfortable if you're highly sensitive. However, if you enjoy modern Gothic tales dripping with atmosphere or detailed mysteries with complex histories to sink your teeth into, this book is fantastic. The series is truly a gift to book lovers, not only for its gorgeous storytelling and compelling characters, but also because it's a series about books, featuring the most fantastic library imaginable, a charming bookstore, lovable booksellers, mysterious authors, the process of writing, the magic of storytelling, and the powerful, undeniable hold that a treasured book can have on a reader.I was a fan of all previous books, but if readers of the series were disappointed in The Angel's Game or The Prisoner of Heaven, fear not. The Labyrinth of the Spirits is Carlos Ruiz Zafon as his masterful best. Despite its length, the story flew by and every page felt necessary and engaging. I will be returning to this book, and the series, many times in the future. The atmosphere and level of storytelling are unparalleled.