Cassidy Wilson is an Immune. No, she is more than that - she is a Verde.
A gene sequence common in those with green eyes keeps her safe from the Pulse, a virus released in the US at the turn of the century - the next century, that is.
Cassidy's special advantage, paired with her wit and physical abilities, have brought her into the world of the Verdes - the special police force of Quarantine, keeping in check the crime that comes when everyone's days are numbered.
As Cassidy trains to lay down her life in order for the people of her continent to die in peace, she uncovers the past of the Pulse, and through it, her own past. But can she handle it?