"This stunning stand alone from the author of New York Times bestseller The Tourist, follows the people on all sides of a domestic terrorist group, from the group's converts to the FBI agents investigating them. New York Times bestselling author Olen Steinhauer's next sweeping espionage novel traces the rise and fall of a domestic left-wing terrorist group. Told from the individual perspectives of an FBI agent, an undercover agent within the group, a convert to the terrorist organization, and a writer on the edges of the whole affair, this is another tightly wound thriller, and an intimate exploration of the people behind the politics, from a master of suspense"--

Summer, 2017. About four hundred people leave behind cell phones, credit cards, jobs, houses, families-- all on the same day. Kevin Moore is one of them. Former military, disaffected, restless, Kevin leaves disappears-- into a movement that calls itself the Massive Brigade. Are they a protest organization, a political movement, or a terrorist group? The FBI doesn't know-- but isn't taking any chances. Special Agent Rachel Proulx is very familiar with Martin Bishop, the charismatic leader of the Massive Brigade. She knows they need to find these people before they put their plan into action. And what she uncovers will shock the entire nation. -- adapted from jacket