When I read The Alchemy of Forever last year, I remember loving the book for its unusual premise, and I remember thinking it felt like that type of story had not been done before, even if it had. Though I am not sure, all I knew was that I had never read about alchemy and immortal souls. The book was not perfect, but what it lacked in execution, it made up for in plot and excitement. I would have never thought I was able to feel for a character that kills each new body she switches to. But I did, and I wanted Seraphina to get away from Cyrus and find her happiness.The Impossibility of Tomorrow starts out where the first book ended, with that brutal cliffhanger that I still remembered as being one of the most unfair cliffhangers I have ever read. It was outright emotional manipulation. It pissed me off. I was angry. I don't like books that do that, and back then I was not marking down for cliffhangers like that. If I read it now, that book would have gotten three stars. But since I don't change my ratings, it stays a 4. This book, surprisingly, gets off to a pretty boring start. Based on that cliffhanger you would have expected some major excitement in the beginning. But not really. That being said, I was really invested in this story after the first book, so I dealt with the slow beginning. I never really thought the book was boring, but I was underwhelmed. The plot of book two is pretty simple. It's Seraphina/Kailey trying to figure out what body Cyrus is in now so she can kill him. There are a lot of suspects, and it's pretty fun trying to figure out who is who. The author nicely places red herrings in the narrative to throw you off, and though I would have liked the mystery aspects to be a little smoother, I was never completely sure who it was all the way up until the end. I had narrowed it down to two suspects, and it WAS one of those two, but I was still thrown for a loop, so I have to give the author credit for that. I thought it was a unique way to write a whodunit and I just adore books that do it well.I didn't find this book to be as good as the first though. There was something missing that I can't put my finger on. There was a lack of action in this one that was present in the first. The sequel is very conversation driven and the book almost feels like a series of conversations that propel the plot along. Many books are like that, of course, but I feel like it stuck out in this one in an obvious way. Towards the latter half of the book, the pacing picked up and then I was dying to know what was going on, but I wasn't completely engaged until about the halfway point. Obviously I liked it enough to rate it three stars. And I'm not sure if this series is done now because the ending, though concluded, was a bit open ended. And you know what? I really liked that. I like when books aren't perfectly tied up with neat bows. It's not an unsatisfying ending at all. It's just different and not what I expected. Another thing that surprised me.So why only three stars? Well, the uneven pacing, and the fact that there were some small issues that irked me. For instance, a character calls the hospital twice and gets patient information over the phone that would never be released over the phone to anyone but a family member. She was NOT a family member. Hello, lawsuit. That would never happen. Then there was a stupid line about a knife being worthless because someone was running at the protagonist with full force. So she throws the knife to the side!! How damn stupid is that? Like what the fuck. How about holding that knife out in front of you so that person runs right into it? DUHDUHDUH. Stupid instances like that had me eye rolling and knocking a little off each time it happened. I don't do bad writing well. So yeah, uneven writing is another reason. I've noticed a couple of times now that Simon and Schuster books have sorely needed some developmental editing. I do hope they get some talented people and increase their editing budget. It's needed. Final verdict? A very positive 3 stars. I think this author has a lot of talent and she's a great storyteller. The writing needs a bit of work but I Have every confidence she can get there. I would happily read her next book. Also, this series is very heavy on the romance and is about a human in love with an immortal. It's interesting in that it's the female that is the immortal, but if you are a reader that has trouble with that theme and the angst it brings to the narrative, I would advise skipping these books.