Bones in a backyard bomb shelter reactivate a San Francisco cold case and a painful connection for Raveneau after missing Ann Coryell's desperate call for help a decade ago. But he sees something much darker in threats made by online followers of historian Coryell's writings on genocide. Nothing pieces together, but all the pieces fit . . . Raveneau edges closer to a core group who are certain the time for retribution is now, but will he be able to stop them in time?