I enjoyed the buildup of the first 150 or so pages unconflicted, but man I am just not equipped to tolerate YA romance anymore--especially in a book like this where the bar starts out so much higher than usual, with not just one but two kickass female protagonists. Natasha and Ava together are very cool, and even though it drove me crazy how much Alex was just there--constantly trying to be the hero of a story that's not his--I have to at least appreciate that Ava just did not allow it. Every time he tried to tell her what to do, she shut him down. Every time he tried to take charge, she and Natasha reminded him whose story it was. It was so annoying that they had to do that for over four hundred pages, but at least they did do it. 
 The romance was godawful. Look, this is Black Widow we're talking about. She's an Avenger. This book has S.H.I.E.L.D. and the Red Room and spies and international intrigue. It is exciting shit, and Ava is a tough, smart character who faces some emotionally complex situations. The story could've stood on its own without the appallingly over-the-top romance, and maybe then it wouldn't have had to be over four hundred pages. 
 Oh, and I almost forgot the typos. I couldn't believe how many there were, and how blatant: the first "A" missing in "Ava," a few places where the edited words were left in alongside the original ("he would never wanted to let go"), once even an entire sentence just duplicated. 
 All things considered, for someone who has a more moderate response to unnecessary and implausible love stories than I do, this book would probably be a lot of fun. I like the format of a Marvel novel, and there was plenty that I did enjoy despite the frustrations.