Starts interesting, but finishes a bit weak
937666
"Think of a number" starts out fine: An interesting premise, some surprising twists, intriguing riddles. Unfortunately it can't sustain this momentum: The subplot about the investigator's marriage sometimes feels forced and pointless, some later riddles are very easy to guess yet the police takes forever to figure them out, and parts of the plan only work because the policemen in the book never pursue some avenues real-life investigators would. Furthermore, the finale feels a bit drawn out, "revealing" things long after the reader already figured them out.

Still, it kept my attention until the end, even if it left me a little bit disappointed. It's a solidly written freshman thriller, and the first and second act work very well.
1728780
I would give 5 stars to the first half of the book, which was brilliantly written and set up a fascinating premise.  The second half deserves two stars, at best.  It can't follow through on what is promised in the beginning, and the story loses its direction and momentum.  It meanders around and can't seem to decide what it's trying to do.  Since the end of a book is more important than the beginning (a strong end can make up for a weak start but not the other way around, in my opinion), I landed on three stars as a fair measure of this book.  But that first half is so great...
2542525
Seraphim has an original premise and a lot of interesting ideas.  It started out well, and I really wanted to like it, but the more I read the more it began to feel like a chore.  The book keeps introducing new concepts and strange powers/events, all of which are interesting, but keeps most of them very shallow.  What really kept me reading was a desire to understand these elements, but by the end of the book hardly any are explained or expanded.  The explanations that do exist are mostly in the form of last-minute info dumps.  I was also disappointed in some of the characters' reactions to the events-in particular the parents' calm acceptance of what happened to Amy early on (I won't go into detail to avoid a spoiler).  Overall, I think the author has an incredible imagination and great concepts, but needs to narrow his focus and cover a few ideas in greater depth.
4594441
The timeline approached started out ok, but got slightly tedious towards the end
4390547
Enjoyable, although pacing in the first half is uneven.
217133
The premise was really intriguing, and the first few chapters make one want to read more, but as the book goes on, it feels like it doesn't really know where it is headed.  After a while, about three-fourths of the way through, I really didn't care anymore about the main characters or what happens to them.  I quit.
4027716
Bit lame beginning, but improves along the way.
3349350
While interesting, and a good first book, the later half feels rushed.
86607
This book started out interesting but about 2/3 into it, it lost its intrigue.  It started with good characters, interesting twists, and captured your attention. I thought the subject matter sounded interesting and then it turned into a somewhat silly horror story.
3971365
I admit, it took me a while to get into this book.  I started it and stopped it at least three times before I finally kept at it.  When I did, I was glad I did.  After finally getting into it, I was intrigued and enjoyed the premise of the story.  However, the second half of the book just seemed pointless.  It really fizzled out.  I kept asking myself why I am reading this.  It had a good beginning, it could have been a great book, but the author decided to steer it another direction after spending so much time developing the beginning of the story.  At least the ending brought closure to the story.  The author did take his time telling the audience where and what happened to each character.

Overall, the book was ok.  It was just ok because it had potential to be great.  Sure, the idea of the story was good, the character development, etc, but the storyline direction didn't make sense with the premise.  Anyway, to each his own.  I suppose others have rated it higher because of its originality, premise, characters, and so on.  I agree those were all great, but it was the enjoyability factor of the second half that did it in for me.
1297148
The first chapters were interesting, then it became cheesy and predictable
4317706
This novel starts brilliantly, with an intriguing premise, a strange world and culture, and a cast of interesting, complex, yet likable characters. It's unfortunate that it peters out at the end, with a conclusion that manages to feel both rushed and hanging. I get the feeling this might have made a better duology, an idea reinforced by the five-year "jump" that occurs in the middle of the book which, while it ultimately makes sense, is nevertheless jarring.

My favorite aspect of the book is the fact that it presents all sides of every situation, from every perspective.  We're first led to sympathize with the Pandoran's refusal to allow refugees to immigrate to their planet, then later to demonize them for it. Likewise, the interplanetary Authority and its representative, Beleraja Poulos, are first painted as bad guys, throwing their weight around and using force and terror to bully the Pandorans into helping them. Later, as we learn more about Beleraja and the situation she faces, we start to respect her courage. Zettel refuses to paint her characters in black and white; each has complicated motivations and conflicting values and it's quickly obvious that there's no "right" solution.

Even the situation presented to the two main protagonists, young sisters Chena and Teal Trust, is fraught with "do the ends justify the means" quandaries. Told their genetic makeup is uniquely suited to creating a cure for the mysterious disease striking colonized worlds across the galaxy, they are nevertheless hesitant to allow the Pandorans access to their bodies.  Their qualms are perfectly understandable, yet also selfishly motivated. What if the Trusts could save lives through the sacrifice of their freedom (or perhaps lives)? Would it be worth it?

Zettel, unfortunately, makes little attempt to answer this question. The second half of the book seems to lose focus, dissolving into a confusing jumble of double-crossing. The scenes with the city-mind of Pandora, an artificial intelligence named Aleph, are so full of promise yet so ultimately confusing and secondary to the main plot that we are left frustrated.

Yet overall, this is a fascinating book with a lot of great ideas. The images of the ecology of Pandora are great, as are the descriptions of the unique culture the Pandorans have created to protect it. And Chena and Teal Trust are absolutely believable as adolescents and sisters, flawed yet likable and resourceful. I would definitely recommend this to anyone who likes intelligent science fiction.
1083246
An interesting read that floundered in the middle and near the end but held up in most places mostly in the first chapters.
2237774
This story starts (and continues) with a really interesting premise: that scientists tinkering with one concept end up accidentally discovering one that seems to turn the laws of physics on their head, and creates an opening for persons with evil intentions to use the accidental discovery to their advantage, and shuffle the existing power structures on Earth. Both of those ideas are compelling. But instead of building THAT story line, the authors choose to focus on the small and petty base impulses, grudges, and emotional traumas of a few individual characters, which turns what could have been some really good sci-fi into a really slow, boring soap opera.
2318154
A young scientist studying links in genes to the potential for criminality  comes across two men, identical down to their DNA, raised separately and  born on different days. As she investigates, becoming more involved with  the law abiding twin, Steve, she discovers that there may be a third twin  still at large, who may be guilty of raping one of her friends.
This  starts off well, as an interesting yarn, but rapidly goes downhill,  especially when the words 'perfect soldier' leapt out at you. Right after  that the story falls flat. Clones and killing machines have been done  before, and combining them doesn't make any difference. The text is bogged  down in unnecessary details, such as obsessive details about how the female  lead dresses, and the ending is decidedly flat.
Follett can do amazing  thrillers and fascinating historical fiction, but this isn't one of them.  Aeroplane reading, but not much more. (It gets three stars for being  interesting at the start.)
3376927
The book is a history of kitchen implements around the world and starts out pretty strong.  As it goes along, the writing style fails to keep your interest as high as at the start.  Not in the same class with other food-related histories like "Salt"
2603557
Not bad, but could have been better.  On the plus side, this does capture the feel of the 1930's and Fascist/German control, in Florence, and starts off with a good, nuanced view of British fascist-leaning politics (which interested a number of highly intelligent and eventually quite anti-Nazi intellectual politicians (I am thinking of Harold Nicholson).  On the minus side, there is a bit much of the romance/sex element for some readers, i suspect.  Not that I'm against that, but the mix -- personal politics, high politics, cloak-and-dagger and sex -- doesnt always work well together.  But if you like this kind of thing, this is the kind of thing you will like -- reasonably accurate, reasonably intelligent.