If you're familiar with Snyder's Study series, you'll be aware that some readers have remarked on how perfect her female characters are portrayed. I'm glad to say that in Spy Glass Snyder seems to have toned down these aspects for the third & final book in the Glass trilogy. (Although fans will be interested to know that there will be another book set in this universe & from the title of Ice Study, it appears that it will be another Yelena novel.) 
 Opal has lost her magic. Out of a sense of preservation for herself & all around her, she voluntarily siphoned her own magic into the form of diamonds in order to keep it out of dangerous hands. The experience has left her a wealthy woman (she got to keep the diamonds) but also a shell of her former self. Then Opal discovers that when her previous captors had been taking more blood from her than was needed for their rituals, which means that there is still some of her blood out there. Which means that she can use it to get her powers back. In order to discover the whereabouts of her blood Opal travels to where Devlen & the others are held prisoner. She assumes that with some effort she'll be able to reach them. However, Opal never expected that it would be so impossible for her to get into the prison... or that she'd find herself so drawn to Devlen. With other people searching for her blood with sinister intentions, Opal may find that the old gypsy saying is true: "Be careful what you wish for- you just might get it." 
 If the Study series was focused more about magic & action, the Glass series is focused more about romantic entanglements & tenacity.While Opal did spend a good chunk of Sea Glass feeling sorry for herself, Spy Glass finds her attempting to find a cure for her magic-less condition. There's also a strong focus on the love triangle between Devlen, Opal, & Kade in this book, which would have been a little more interesting if Kade had been more prevalent in the book. 
 Overall, the number one thing about Snyder is that she always seems to have a way of making her books into addicting reads. Even though Spy Glass might not be my favorite of her books (Poison Study will always take that spot), I couldn't help but keep turning back to the book in order to find out what happened next. Other readers will find themselves equally as hypnotised by this book, unable to turn away until they reach that final page. A warning though- keep an open mind during this book. I'd thought that I'd had everything figured out in the middle of the book, only to discover that my assumptions were wrong about almost everything. Let's just say that some people might get a little surprised about the villain's identity & who Opal's knight in shining armor will be. 
 The final verdict? Long time fans of the series will like this book while those who weren't Opal fans might find themselves yearning for more of Yelena. Rest assurred though, there's enough to like in this read & I'm curious to discover what will happen next in Snyder's world. As always, Snyder writes an addicting read. 
 (ARC provided by Netgalley)