The sirens are back, but Vanessa may be the biggest threat of all. . . . 
 Why's Vanessa the biggest threat? The author gave us no ending about what happened to Vanessa next. Just said she added some "victim" in the water. Why did she do that? (Yes, good for her health? Do you truly believe that?) and what happened to her father? Who was that "Charlotte "? What would her life become after all those changes? We're about to find them all in this book. 
 A little bit disappointed when I first finish this book...what I read was just...nothing. Vanessa got back to her normal life, without siren...but with the company of Simon. Yet her happiness didn't last long, she scared her new identity and wouldn't face it with Simon. Why does the second book often the worst one in trilogy? (Sigh...) I've expected so much on it. I wish to read some of Simon and Vanessa's relationship and what did she discover about herself. Yes, I can get some of them, but to me, Vanessa was too afraid to face them all. I don't like Parker at all, but after I read the third book...I sort of forgive him. (You'll know why when you read it, but at the meantime, lady and gentleman...just finish Undercurrent first!) This book is mainly about the new life she was forced to adapt, and some detail that connect the first and last book. So as you can see,,,connecting details are often boring and unforgiveable. Fortunately, this book still gives us something to read after all those heartbreaking and terrible deaths. The hideous-beautiful-haunting sirens are back! (By the way, I heard somebody complain about "Siren" isn't what we usually know from the Greek mythology. But please, Siren has already transformed into a word that means those beautiful women who hunt by their voice. They don't necessary have to be mermaid or some magical forms) I must say, their returned kind of force Vanessa to accept who she was and what had happen to her life. As I mention at Siren's review...you can't see all the well connection if you never finish the whole trilogy. But once you re-read the trilogy...you'll stick yourselves inside the story. (Perhaps some of you like it for the first time...but at least for me,,,I truly love it until the second time I read. And I can forgive all the sacrifice that Vanessa made.) 
 This is originally posted on my blog 
 Vivian's Book Pavilion 
 http://viviansbookpavilion.blogspot.com/