Mackenzie Day is finally back in her own body after she was imprisoned by the Potestas-a group of mind-reading terrorists-and forced to watch while they used her to infiltrate her home, her friends, her family, and her livelihood. Now, as the threat of Zero-a deadly chemical the Potestas are using to manipulate the world-becomes more prevalent and the situation escalates, Mackenzie must go deep undercover into enemy territory. What she finds while among the murderous extremists might easily be her undoing, unless she can look deep inside herself, find her inner strength, and stay UNDIVIDED.