I loved that West filled this last book with so much action and suspense. Usually, with these last books there's too much build up, a lot of waiting around and planning, and then things are rushed and action-packed at the very end. Here, West gives us plenty of action scenes scattered throughout the book and one heck of an ending to finish it off. There is build-up and waiting around, yes, but it wasn't boring at all and it was necessary to the story and with what the characters went through. The villains got on my nerves so much, I don't think I would've been able to restrain myself in Ari's situation. There's also a lot of twists and turns as the plot unravels and you never know who to really trust. 
 Ari was such a fantastic heroine, especially in this book. She just came off as kickass. She really changed a lot throughout the series and become such a strong leader. I also liked that, despite her wanting to be reckless and driven by emotion, she kept a level head and focused on the bigger picture, i.e. the war. Of course, her passion and love for Jackson was palpable, but she never let it overshadow what she needed to do to beat the bad guys. But, let's talk about Ari and Jackson. You don't get many romantic scenes between them because of everything going on, but what little we do get was awesome. Sure, nothing beats that shower scene in Hover, but they do have some sweet and tender moments that made me smile. 
 I have to admit, I forgot much of the rest of the series because it's been so long since I read it and it was a little hard to follow along at first, trying to remember what happened and all of the key players in the story. I recommend binge-reading this series to get the complete picture because you'll appreciate the story better that way. 
 Either way, Collide was a pretty decent conclusion to the series and I was very satisfied with the how it ended. Be prepared for a lot of deaths in this one. It is a war and not everyone makes it out alive, sadly. The Taking is definitely a great sci-fi series and if you're already a fan of it, I'm sure you'll appreciate how everything ends. Oh, and I loved that epilogue, by the way. Excellent!