Gravity, oh gravity I had such high hopes for you. The synopsis was so intriguing, I am not sure there was any dystopian/Sci-Fi fan who wasn't anticipating this novel. I just need to point out first that I read an early edition and I have heard many changes occurred, most of which I had problems with so keep in mind that many of the issues I will mention have probably been rectified. 
 In Gravity we've got two species, the humans, and the Ancients. You really don't know much on how the Ancients arrive or their relationship to humans or why they do things called The Taking (even after I finished the book I really didn't get it). However Ari finds out who her Ancient is and is surprised that it is Jackson, the most popular guy in school and her rival for top seed in school and becoming an operative. I felt Ari was a bit naive and very easily manipulated to give any information one needs even if it betrays her father. I also felt like the world building was a bit weak and while the beginning didn't give much, and that helped in keeping the readers on their toes, I hoped by the end I would have answers to many of my earlier questions. 
 However I really loved the last couple of chapters for the novel. The direction Melissa West, while not all that unique, was still one that got me excited for the second book. The whole biological warfare and the struggle between wondering whether the Ancients were good or not and what their world was like was what made me enjoy the novel in the end. I won't really mention the romance because I personally tried my best to ignore it. It was too insta love for me but I'm glad it didn't overshadow the main plot. I do hope a love triangle (gasp!) would emerge in the second book, but not a flimsy one where Jackson still ends up with her, no competition, but one where the other guy might just get her in the end! as the saying goes, all's fair in love and war. 
 I do recommend this novel, especially the edited and modified edition for the readers who found the synopsis to be intriguing. Give it a try, I am pretty sure if I read the changed version I would have liked it so much more! I recommend this to fans of The Shadow Society by Marie Rutkoski and Sci-Fi/Futuristic genre lovers!