I think if I had to pick one character's books to read in sequence, I would pick Marco. Much as I love Cassie, Marco's storyline is the clearest and strongest throughout the series so far (with less repetition than Tobias).
We are finally moving forward with the main storyline. Here's a turning point. There's no going back. The book is a good balance of set up and action. Can't wait to see where this takes us.
A couple of questions under the cut.
When did they discover the Yeerk entrance at the car wash? I don't remember that at all.
Why does the Bug fighter need to be at a certain velocity to enter the ocean? I didn't understand that at all. Also, the entrance to the underground cavern is pretty deep under the ocean yet it's also just a short tunnel from the Yeerk pool? I know the Yeerk pool is large, but is it really that large? Did they make the pool cavern itself larger when they added this tunnel to their underground hangar?
We know from The Proposal that Nora wasn't a Controller when she started dating Marco's dad. So why is there all this uncertainty on Marco's part at the end of this book? Is it just a case of the ghost writer getting mixed up? I think it would be more interesting (and probably more Marco-like) if he just lied to his dad rather than the "desperate speculation" the book makes it out to be. No, it's not speculation. It's self-service. Marco's family is reunited and he has a way to keep Nora away and eliminate that complication to his happy ending. We'll just have to see what happens because of this (because I can't remember...).