Vanish was a disappointment for me as I had enjoyed Firelight with this new draki mythology. It wasn't all that bad as there were a few surprises here and there that excited me. However, when you look at this novel as a unit and not by its parts, you can like I have, diagnose Vanish as having Middle-Book Syndrome. It's as simple as that. Hopefully Vanish is not an indicator of how the third and final book in the trilogy will be like. 
 Vanish begins where Firelight finished. Jacinda reveals herself to the hunters in order to save Will from his death, forcing Cassian to take Jacinda, Tamra and their mother back to the pride. It is within the first chapter that we discover who the beauty that is on the cover, is, and I will agree; it is was possibly only one of the two surprises in the book that saved it from the dreaded two-star rating. But this discovery is the reason and can be blamed for the rest of this 'filler' plot. I don't want to spoil it for anyone who has not read Vanish yet so I will go no further in this discussion. 
 I will try and describe what occurs in the rest of the book after the first chapter. It is just about Jacinda wanting Will, Cassian wanting "someone" and then also Jacinda, and then someone else wanting Jacinda, and Jacinda not wanting him and him, but wanting him, and someone wanting someone and you lied to me no you lied to me why why why stop creeping me out stop following me stop stalking me I want to be with him not him and him and why does she get to have him now well she can have him I dont want him I want him and not him... I could go on and on but I'm hoping that you get the picture? I guess, you're asking if there's a Team Will or a Team Cassian. Yes there is! But there then develops a pentagon, rather than a triangle, with these two new additions which pressure Jacinda's decisions in her angsty teenage love-life. 
 There's not much more I can really say about Vanish as I pretty much summed it up in the previous two paragraphs. But me being me and pledging myself to that saying, "Once I start, I just can't stop!" I am looking forward to the final book, in hope that Sophie Jordan will execute a more thrilling and heart-racing story that she did not achieve already. If Vanish were the directions from getting from A (Firelight) and to B (Firelight #3), I would have been lost. There was just no major progress.