The Passage sucked me in immediately with descriptive character connections and I devoured the first 200-ish pages in a matter of hours. Then everything from the first part of the book disintegrated in a way that left me feeling confused and somewhat annoyed for about 100 pages.
Regardless, I stuck with it, muddling through the new section of the book with hope the style and narrative would hook me back in. Eventually it did, but not to the same capacity the first part of the book did.
I found the new characters and their situation interesting, but the way Cronin approached introducing them was confusing. He invented scenarios to try and explain the strange new world these people lived in, but for some readers I can definitely see how this shift in events could be a turn off.
Overall Cronin's approach to the vampire genre was different and fresh. There was nothing romantic about these icky beings, but you could identify with both the people and the vampires to a certain degree. The evolution of the main character, Amy, who started out as a 6-year-old girl and evolved into a 16-year-old/90-year-old vampire, was a little predictable, but she was the best thing about the book.
Apocalyptic in nature, it reminded me just a little of Robert McCammon's Swansong with a light smattering of Stephen King's The Stand woven in as well before dashing it with vampires to make it unique. In a world obsessed with romanticizing vampire in literature and movies, it works.
I have not read any of Cronin's other work, but I might be interested to check it out to see if his writing style differs, if The Passage is an improvement or a scattered project that grew beyond Cronin's control.