Title: Midnighters #3: Blue Noon by Scott Westerfeld
Genre: Young adult, sci-fi, action
The darklings have found a way to expand midnight so that all humans will enter the blue time and become prey. Complicating the crisis is Rex's residual darkling characteristics that leave him with the unsettling notion that other humans are food, Jonathan's secret desire that the midnight hour could last forever so that he would always be free of the confining flatland gravity, and the fact that no one has yet figured out why the darklings wish to dispose of Jessica Day.
Comments: I particularly liked the fact that in this book the Midnighters start questioning the morality of how they and previous Midnighters have acted. The book ends with an unexpected twist and while the story is mostly resolved, there is the opportunity for further Midnighters' books.