Explain what Sydney means when he says, “I heard the fall of the axe in that sound.” (From Book 3 Chapters 11-15)

Doctor Manette goes out to try to use his influence to save Darnay again, but everyone doubts he will be successful. Carton agrees with the rest that there is no hope. Mr. Lorry laments that the lives of men mean nothing anymore. After the demonstration in court Sydney could almost hear the axe fall for Darnay.