Mr. Lorry arrives at the Paris branch of Tellson's Bank. It sits next to the former house of a grand French noble that has been converted into an armory for the revolutionaries. In the courtyard there's a large grindstone.
The house's transformation symbolizes the Revolution: formerly representing the excesses of the nobility, now the house represents the revenge that excess inspired.
Mr. Lorry is stunned when Lucie and Dr. Manette rush in. They left London immediately after reading Charles's letters. Dr. Manette's fame as a Bastille prisoner has granted him access and information, and he has learned that Charles has been imprisoned at La Force.
In his return to Paris, Dr. Manette represents redemption through suffering. He's been restored to his former life, and suffering has earned him political power within the Revolution.
Noises outside draw them to the window. Half-naked men covered in blood are turning the grindstone to sharpen swords. Frenzied, blood-smeared women pour wine into the men's mouths. The mob runs howling into the streets with their weapons.
The revolutionaries are described as uncivilized savages, engaged in some terrible ritual. Note the wine-blood connection and the intoxication of violence.
Mr. Lorry whispers to Dr. Manette that the mob has gone to kill the prisoners at La Force. Horrified, Manette runs out to the mob. Manette and the remaining revolutionaries rush to La Force as the mob cries out, "Help for the Bastille prisoner's kindred in La Force!"
It is not enough for the revolutionaries to imprison their enemies. They must kill them. Manette, though, uses the political power he gained from his sacrifice to save Charles.