What part do Mon. and Mme. Defarge play in the storming of the Bastille? (From Book 2 Chapters 21-24)

Defarge and Madame Defarge serve as leaders in the mob that is storming the Bastille.They are euphoric as they literally feel swept into the prison to exact revenge,

Over the lowered drawbridge, past the massive stone outer walls, in among the eight great towers surrendered ....So resistless was the force of the ocean bearing him on, that even to draw his breath or turn his head was as impracticable as if he had been struggling in the surf of the South Sea, until he was landed in the outer courtyard of the Bastille.