I went into reading The Infinite Sea thinking it would be as action packed as The 5th Wave. I think this is where my 3 stars has come from compared to the 5 stars that I gave The 5th Wave. 
 I still loved the characters and seeing specific characters (like Ringer) evolve and hear about why they act they way they do, and how they became to be the person they are after the first four waves. I also like where the story line is going overall for the group of characters who are trying to survive the 5th wave. So what was my beef with The Infinite Sea? Well, let me tell ya. 
 The Infinite Sea picks up the story where The 5th Wave leaves off, and I think I would have preferred it if the story continued to be told through the same characters' points of view as The 5th Wave included. I really enjoyed Cassie, Evan, Ben (Zombie), and Sam's points of view. This time around, we are given four or five different points of view, but only two of them are carried over from the previous book. While I understand why certain parts were told through specific character's pov (in order for us to understand how events happened as some could easily be thought to have been performed by other characters), I didn't really feel as invested in the characters whose pov's the story was told through because Rick Yancey seemed to skim over these characters and their roles and lives in The 5th Wave. Why would I suddenly feel attached to a character that I was basically pushed into not caring about in the first book? Then, (spoiler alert) I'm given tons of back story about one said character who ends up dying 20 pages later anyway. I understand why it was told through the character's pov, but still... really? 
 Another problem I had with this book compared to The 5th Wave was the lack of action. Most of the action in The Infinite Sea was pushed into the very beginning of the book and the very end. We spend so much time in the head of the character Ringer that this book started to feel like a psychological book versus a science fiction/action book. But Ringer isn't the only character whose mind we find ourselves in. Between Cassie, Evan, and a few others, this book felt like it took me longer to read than the week that it did. The 5th Wave has so much more action, intrigue, and excitement that The Infinite Sea felt like a bit of a let down. I still plan to read the final installment in The 5th Wave trilogy because I want to know what will happen to all the characters, but I feel I can only give The Infinite Sea 3 solid stars.