Although we are never specifically told what it means to be kept "in secret," we can infer what it must be by looking at what happens to Charles Darnay in Book the Third, Chapter 1. Darnay is taken through the general populace of prisoners, who sympathize with him for his sentence of being kept "in secret," assuring him that others have had the same misfortune, and that it is generally not for long. It appears that "in secret" refers to an extreme kind of solitary confinement. Darnay is taken past the regular prisoners, up forty stairs to a cold, dark, solitary cell measuring only five paces by four-and-a-half. Here he is not to be allowed to have paper and pen, only food. There is nothing for him to do but pace the room and try to keep from going mad like his father-in-law Dr. Manette, who, when in prison, "made shoes."