Pip’s old guilt resurfaces when he learns that convicts—more specifically, convicts with leg irons that have been filed through—are suspected of the attack on his sister. The detectives who come from London to solve the crime are bumblers, and the identity of the attacker remains undiscovered. Mrs. Joe, who is now unable to talk,
begins to draw the letter “T” on her slate over and over, which Pip guesses represents a hammer. From this, Biddy deduces that she is referring to Orlick. Orlick is called in to see Mrs. Joe, and Pip expects her to denounce him as her attacker. Instead, she seems eager to please Orlick and often calls for him in subsequent days by drawing a “T” on her slate.