This book felt like a lot of untapped potential. I think it's mainly bc I didn't like the mc for the first half of the book. I found him annoying, and the emo "darkness" bs felt like a whiny 14yr old. I really wish there was more about Samual and Bria. Once Bria and Eli have sex, most of their subsequent interactions are sex. So if you want a smut book this definitely does that. I will say some of their intimate conversations are genuinely heartfelt and beautiful, one of them had me shed a tear. 
Overall, a very mixed experience. Every time I thought, "oh okay, this is it" something cringe happens for no reason. Marrow was better, but this was definitely a fun and fast read despite its pacing, I finished it in 24hrs