Blue time occurs at Midnight and time freezes. There are only a select few people who can go out and walk around in the Blue time, and they are called Midnighters. When Jessica, Jonathan, Dess, Melissa, and Rex are in school the blue time happens at 9 am, they become concerned and wonder why Blue time is happening during the day. Rex and Melissa go and visit an old mindcaster that is still in Bixby and she tells them that the darkings are responsible for the Blue time happening during the day. The darklings plan on expanding the blue time to encompass the world so they can feed on humans whenever they want with no one to stop them. The Midnighters come up with a plan to stop the rift the darklings have opened up, but what sacrifices must Jessica, Jonathan, Dess, Melissa, and Rex make to stop the darklings from overtaking the world as they know it?
This book was a very good ending to this trilogy and it left a few things open if Scott Westerfeld wanted to continue the series. I recommend Midnighters 1: The Secret Hour and Midnighters 2: Touching Darkness also by Scott Westerfeld to see how it all began.