After her last assignment went horribly wrong, everyone tells FBI Special Agent Lexie Montgomery she needs a break. But Lexie is determined to keep going with her undercover work—so when a Dutch constable goes missing, she jumps at the chance. Along with Blake Bennett, her unfamiliar new partner, Lexie is thrown into the Gathering, a haven for environmental activists planning illegal activity. It's a dangerous situation, but she blends right in—a little too well, Blake thinks. As the pair of them try to get closer to the vanished constable, he begins to suspect that Lexie may be hiding an affinity for the eco-extremists' cause. With her loyalties in question from both sides, Lexie will be forced to prove herself as an undercover agent and as a new recruit for the terrorists' cause. But as time starts to run out, staying below the radar may prove harder than she'd planned.