The Second Period, subtitled "The Discovery of the Truth: (1848–1849)," begins with the narrative of Miss Clack, Sir John Verinder's niece, and Rachel's cousin. Miss Clack, in her self-righteously pious tone, explains that she is currently living in Brittany and has received a letter from Franklin Blake asking her to relate the events Miss Clack witnessed while visiting with Rachel in London during the weeks after the diamond theft. Footnotes added by Franklin Blake assure us that Miss Clack's narrative stands unaltered. Miss Clack relates events accurately by consulting her diary.
Miss Clack first visited the Verinders shortly after they arrived in London, on Monday, July 3, 1848. Lady Verinder sends word through Penelope inviting Miss Clack for lunch the following day. Miss Clack leaves Christian pamphlets for the household.
Miss Clack proceeds to her Christian charity meeting. She hears from other charity members that Godfrey Ablewhite, their leader, and another gentleman, Septimus Luker, had been attacked the previous Friday. Godfrey and Mr. Luker accidentally met each other at the door of a bank on Friday, and both proceeded home. On arriving home, Godfrey had found a boy waiting for him with a note asking him to come to a house on Northumberland Street in one hour. At the Northumberland Street house, Godfrey is shown in. While he was busy looking at an Oriental manuscript on the table, he was grabbed from behind by a brown arm, bound, and gagged. He was searched and left in the apartment to be found by the landlady. She explained that the apartment had been let, through a respectable gentleman, to three Oriental noblemen.
Miss Clack also hears that later that Friday, Septimus Luker the moneylender was similarly attacked in a different building. The attackers took from Luker a receipt for "a valuable of great price" that Luker had just received. The authorities assumed that the Indians were after Luker's receipt and the attack on Godfrey was due only to his random association with Luker, when they met at the door of the bank.
Miss Clack arrives for lunch at the Verinders' the next day. She is shocked by Rachel's unrestrained manner and "feverish excitement," especially around the subject of the attack on Godfrey. After Rachel leaves the room, Lady Verinder explains the theft of the Indian Diamond to Clack and describes the doctor's orders to keep Rachel occupied and amused so she won't dwell on it. Miss Clack warns Lady Verinder that Rachel seems to be keeping a secret. Godfrey Ablewhite's arrival is announced.
Miss Clack, with great admiration, describes Godfrey's perfect entrance and his perfect humility in describing the attack upon him. Rachel comes in and asks Godfrey to describe the attack and becomes suspicious when he is reticent. Miss Clack is disapproving of Rachel's forthrightness.