Absolutely incredible read. The Song Rising had a fairly clean ending, so I was interested to see where The Mask Falling would pick up - I was not disappointed. This book introduced tons of new, interesting, diverse characters and the plot sprinted forward. The only reason I didn't rate 5/5, is that I felt (especially toward the end) that Shannon was rather frantic in her writing; I felt the last 100 or so pages didn't need to be as rushed as they were. I am, of course, also devastated by the ending, which leaves me with so many questions I was truly in shock. It seems that Cade is the Devil, AND A FELLOW DREAMWALKER, and Arcturus remains the Lover. But now, we have no idea if Arcturus survived the bombing in Paris. This will be on my mind for quite some time. I also felt that some of Paige's escapes this book were a bit shocking. How many times will she slip through Nashira's fingers? The break-in at Sheol II seemed to happen so fast, and rather easily. I wonder if our characters could've endured more challenges during that sequence of events to make it more believable. Watching Paige and Arcturus learn more about one another was a highlight of this book. Their relationship is so interesting and adds to an already rich plot. I am so excited for the next book, and completely heartbroken that it's over 1 year away.
Overall a decent read. I found the world-building rather slow and confusing, and the motivations of characters weren't made very clear. The latter half of the book was more exciting, and set up for what's likely a better sequel. Definitely aimed at a young teen audience. Quotes: "...Because you're like a story that hasn't happened yet. Because I want to see what you will do. I want to be part of the unfolding of the tale." pg. 101
This book was pretty disappointing compared to the ACOTAR trilogy. The plot was usually nowhere to be found, and when there was some plot development, it was all over the place. There was no reason this book needed to be as long as it was. I enjoyed spending more time with characters from the trilogy that I loved, but other than that, not many positive things to say about ACOSF. At times, it read like mediocre fanfic. 2.25 stars for the smut.