Without a doubt, this is one of the most creative spins in YA paranormal that I've read lately. But then again, I've been smacked in the face with a glut of angels, fairies, vampires, and werewolves, so anything well-written outside of those oh-so-familiar territory is bound to be a Big Effing Deal. 
 So this was what a nightmare looked like by the light of day. 
 The setting is also one not typically seen in YA; turn-of-the-century (1899) Paris. Our main heroine, the 17-year old Ingrid, her 15-year old sister, Gabriella, and their mother are newly arrived to a crumbling, decaying abbey that is to be their new home, while their mother indulges in her much longed-for hobby of opening her own art gallery. Ingrid's twin brother Grayson was charged with helping with the location of such a place, and has spent awhile in Paris. There's just one problem...he's disappeared. Ingrid and Gabby spends the rest of the book hunting down their lost brother, while encountering all sorts of mysterious creatures and events on their relentless quest. 
 The setting is beautifully described, and the writing well-done. I felt all the action scenes were superbly described, and the mystery surrounding everything unfolded in a rational manner, in a way that never bored me, even if the plot and the mythology surrounding the book is something new. 
 And it is something new. When reading a book about werewolves, vampires, or fairies, the reader automatically assumes and expects them to behave a certain way because the legend and mythology surrounding these creatures are so well-known to us. We expect vampires to drink blood, we expect Mab and Titania, Oberon and the Wild Hunt in a story with fae. But here we are introduced to gargoyles, and new sects and terminology that requires new explanations: Dusters, the Alliance, the Dispossessed, the Angelic Order, hellhounds, the Underneath. 
 That's a lot of mythology, a lot of terminology, but it never gets confusing because the author does such an excellent job of incorporating every element to us, in a way that the reader never feels patronized or that they're being not-so-subtly informed. It is never outright told, but everything is eventually explained in a gradual manner, so that the reader does not feel like wringing their wrist or ripping out their hair because they don't know what the bloody hell is going on. The gargoyle mythology is well-developed and so interesting, I love learning about them, that they're bound to protect a household where a statue exists. I can't overemphasize the fact that I was never confused or lost. In so many stories, the built-up setting is sometimes contradictory, sometimes confusing, and the action scenes just leave me completely lost. I was always engrossed in the story while reading this book. 
 The setting is well-done, beautifully described, but never overshadows the story. This Paris has a very Gothic feel, with decaying buildings, ancient abbeys, underground tunnels, and dirty Parisian streets. It never feels overdone, and enhances the overall feel of the mystery. 
 The characters were well-written, and out of the main cast, there was only one who rubbed me the wrong way. Ingrid is an excellent heroine, she is devoted to her brother, headstrong but not stupid, intelligent and unafraid. 
 I found her sister Gabby to be more grating and multidimensional. Gabby, unlike Ingrid, is fiery and very often makes stupid decisions, but that could be explained by her age, although I found it pushes the borders of credibility that she is given so much freedom at her age and at this time. Gabby is hypocritical and contradictory at times, she doesn't blink at the thought of visiting a waiter she met once for information at his room, but hesitates when it comes to trusting people who have saved her life repeatedly. She constantly flaunts the borders of propriety, like dressing up like a bordello girl to visit a waiter at his home for information... 
 Her sister's eyebrows would have leaped clear off her forehead had she seen the dress Gabby had changed into: an evening gown of profane red satin with a black lace overlay and a plunging, black lace-trimmed neckline that accentuated her rather voluptuous decolletage. The gown wasn't appropriate for a girl just shy of sixteen to wear in midafternoon. 
 But then again, a visit to Henri's flat wasn't appropriate, either. 
 ...then acts like a prude when it comes to visiting a known Alliance member when he invites her to step into his bedroom for conversation. She is flighty, contradictory, and endangers herself more than once. 
 Nevertheless, Gabby is overall a believable character, despite of---or maybe because of her flaws. 
 Gabby knew the truth of it. She was pampered. She was most definitely privileged. But if there was one thing she was not, it was a damsel in need of rescuing. 
 Gabby's love interest is the dislikeable character of whom I speak. Nolan is a jerk, overbearing, patronizing, and uninteresting. I can't see the attraction. He is also considerably older than her 15 years. 
 Nolan tugged Gabby against him and smothered her protest with a kiss. His lips moved tentatively over her mouth, hers stunned and graceless, her hands clenched into fists against his chest. 
 Um, a 15 year old girl? Pedophile much? 
 I also had a small problem with Grayson, Ingrid's brother. I can't help but feel that Ingrid is more than he deserves. She is the best sister, ever (spoken by me, who is the worst sister ever), She is absolutely persistent on finding Grayson. Their connection is so strong, she loves him so absolutely, and from what we know of Grayson, it doesn't feel like he is worthy of such devotion. 
 The story is told in omniscient view, which I love. We get to see things from Luc, Ingrid, Gabby, and Grayson's point of view. While the rest of the cast doesn't know what happened to Grayson, we do. The reader knows what Grayson is experiencing, even if it doesn't make much sense at first without the explanation, but we know what Grayson is feeling and experiencing. While Ingrid is worrying herself sick and endangering herself to find out what happened to her beloved brother, Grayson never gives her a single thought. 
 There is a love triangle within the story, but it is not an overwhelming one. The romance, if any exists, is mainly between Luc and Ingrid. If I haven't written much about them, it is not because they're uninteresting in any way, but their characters are complex and the story unique, and I feel these the main characters should be discovered by the reading of the book and not through a review.