The Appalachian Assassin was an unknown saboteur and wanted criminal before the Great War.
The Appalachian Assassin was responsible for planting explosive devices across the region of Appalachia. On June 14, 2077, an undetonated device was found in Berkeley Springs near the Route 65 highway. Boomer, the department's bomb disposal unit, was able to defuse the device before its detonation. The identity of the assassin remained unknown after the incident.
The Appalachian Assassin is mentioned only in Fallout 76.