Dr. Mara Sutton, a top FBI hostage negotiator with a perfect record, faces her most dangerous challenge yet when a series of incidents suggests the existence of a clandestine mind-control program known as Project Threshold. As Mara investigates, she uncovers a network of sleeper agents programmed to respond to specific triggers embedded in everyday communications.

But the deeper she digs, the more she realizes that the program never truly ended, and that its architects are now using its technology for mass manipulation and control. With the help of a whistleblower and a rogue scientist, Mara must race against time to expose the truth and prevent the activation of a catastrophic plan that could reshape society as we know it.

But as she confronts the architects of Project Threshold, she must also grapple with the unsettling possibility that her own mind has been compromised, and that her actions may be driven by programming rather than free will.