Touching darkness - Scott Westerfeld

The Midnighters of Bixby, Oklahoma, know that their town is full of secrets - especially since they keep the biggest secret of all: knowledge of the secret hour, the mysterious time at midnight when the world freezes, except for them and the creatures that inhabit the darkness.

What they don't know is why earlier generations of Midnighters all disappeared, or why they are now the only Midnighters in town. As they learn more about the secret hour's twists and turns, they uncover terrifying mysteries woven into the very fabric of Bixby's history, and a conspiracy that touches both the midnight hour and the world of daylight.

At the same time, the Midnighters' own secrets start to emerge, including some that were never meant to come to light, changing the fragile dynamics among the five. This time Jessica Day is not the only Midnighter in mortal danger. If the group can't find a way to overcome their differences, they could lose one of their own - forever.