An organization more powerful than the Archives hires a deadly assassin to kill black-energy executives. They believe it’s the only way to save their children from the environmental collapse of the earth.

Burke and Alex use their resources to fight them. Alex’s sister, Riley, is a detective investigating the crimes. After years of separation, she turns to Alex for help and becomes emotionally attached to Burke.

As the killings continue, the assassin goes rogue and kills the leaders of the organization that hired her.

Continuing her killing spree she plots to turn Las Vegas convention attendees into bomb carriers by hiding C4 in giveaways. She then goes to Mexico to work for the crime lords. As the Archives pursue her, the team watches the detective become more like the assassin, and the assassin more like the detective.