A plague, called Wickedness, is pulsing through the world; and in its wake, it's dividing the population into thirds:

The WICKED: Already infected by the droves of Singers, the ultraviolet mosquito-like insects who carry the plague, the Wicked roam the world freely. They don't want for much--only to maim and dismember you. But don't worry: They always ask politely first.

The TRUE: The True live in contained, isolated communities. They're the lucky ones; they found safety from the Singers. And while the threat of the Wicked may not be eliminated, for the True, the threat has certainly been contained...

The VEXED: The Vexed are the truly fortunate ones--they survived the sting of the Singers, leaving them immune. But they're far from safe. The Vexed hold the key to a cure, and there are those who will do anything to get it.

In this brilliantly realized novel, three teens--Astrid, Hank, and Natalie--start to realize that the divisions of their world aren't as clear as they seem, and are forced to question what being wicked truly means.