♪ minutes after john wilkes booth crosses the navy yard bridge, sergeant cobb stops david herold riding a gray roan horse. cobb asks if a rider has passed here and cobb tells him yes and lets him pass. his job is to guide lewis powell out of washington after killing secretary of state seward. but hearing the cries of "murder" from seward's house -- >> murder, he's killing my father! >> he flees the scene not waiting for him. he catches up just outside of washington. and it's midnight when they arrive at a safehouse for confederate spies. >> for god's sake, make haste. >> at a tavern where weapons have been stored. a tavern owned by the mother of confederate courier john surrat.