To say that The Ripple Effect is a roller coaster is putting it mildly. J.A. Saare has done a great job with the series so far and it really keeps getting better. 
 The Ripple Effect picks up a couple of weeks after the events of The Renfield Syndrome. Rhiannon is still angry with Disco for what he did at the end of the book, and her relationship with Paine is complicated. Unfortunately Rhiannon doesn't have any more time to sort out her feelings because Mircea (Disco's maker) is coming for a visit and must see Disco and Rhiannon as a united front. If things appear otherwise the half-demon master of the family will feel the need to intercede and no one wants him to visit as well. 
 Besides this Rhiannon still has to find Marigold Vespa's body as well as make good on her promise to kill Victoria Delacroix. 
 As the title suggests this is the world that Rhiannon has returned to from the future and the course it's been set on by her coming back and saving Disco. I've read other reviews and the thing that can best describe this book (and I think it's a concensus) is: Consequences. This book exihibits the consequences of Rhiannon's actions. 
 Rhiannon has been through a lot in the series, and J.A. Saare definitely doesn't let up this time around either. Rhiannon has to come to terms with, basically, everything. She has to decide what things / people in her life are important and not waste time being angry. 
 Like the other books Rhiannon has to face death, the threat to her own life and those she cares about, betrayal, heartbreak, and love. But I like that really nothing is off the table for JA Saare. Just because things happen in one book doesn't mean it won't turn around in the next book (to be replaced with something else) so I'm not too saddened by some of the occurrences in this book because you never know where you'll be taken next. JA Saare is not afraid to make Rhiannon do something that people wouldn't like and she's not afraid to take risks with her characters in general. I think it's what makes this series so good to read. The good people don't alway come out on top and they don't always do good and the evil people don't always lose and sometimes they too exude heartfelt emotions. There's ambiguity and shades of gray. 
 These books are difficult to talk about because there's so much that happens throughout the course and I don't want to give anything away. These books are really best experienced without spoilers. Suffice it to say the chain of events from this book is big and could impact the rest of the series. 
 I can't wait to see where we will be taken next, but with now estimation of publishing date for Edge of Darkness I don't know when we'll find out. But I'm willing to wait. Until Then!