Julia protests that Betteredge should speak to Cuff for her, for her “nerves are a little shaken” and she feels that Cuff “is bringing trouble and misery with him into the house.” She requests that Betteredge accompany her during the interview. Cuff agrees to this proposal before explaining that he has “already formed an opinion on this case” (which he will not yet share) and outlining his plan to find the smeared dress by searching the servants’ possessions. He believes that it cannot be proven the Diamond was stolen, only that it “is missing.”
Like Rachel, Julia begins to push back against the investigation, which overturns the usual boundaries of public and private space in her house, turning everything into a possible clue and putting everyone under suspicion. Unlike Seegrave, Cuff recognizes the impact of his own presence—and, of course, his suspicions—on those around him, and chooses to hide his clearly unconventional theory in order to avoid alienating the family. In doing so, Cuff disrupts the reader’s usual process of discovery about the theft, leaving them in the dark and turning the investigation itself into part of the mystery the reader is supposed to solve.
Julia again resists the prospect of searching the servants, which Cuff insists must happen (although he laments Seegrave’s initial search for showing the servants they were under suspicion). Cuff proposes explaining the whole case to the servants and promising to search everyone in the house, regardless of status. As he leaves for London, Godfrey also agrees to leave his possessions for the search. Cuff asks for a record of the washed linen (so he can determine if any is missing) and again laments that Seegrave openly advertised his suspicions to the servants. Rosanna brings the relevant records, and Cuff asks about her, since he had seen her in prison in the past. He assures that he does not suspect her, or “any person in the house […] up to the present time.”
Cuff’s decision to be completely transparent about what he knows for certain seems to contrast with his insistence on keeping his suspicions a secret—this contrast draws a sharp line between evidence-based knowledge and speculative inference, a distinction that is crucial in detective fiction (where a reader must have at once a concrete sense of what can be known based on the clues and an unprovable suspicion that gets either confirmed or denied upon the revelation of the culprit).
Rachel refuses to let Cuff examine her wardrobe—he is not surprised, and calls the whole search off, since “we must examine all the wardrobes in the house or none.” Cuff is also not at all disappointed; he simply implores Betteredge to “wait a little.” Betteredge writes that he failed to understand what Cuff was thinking, although “cleverer heads than mine might have.” Cuff leads Betteredge back to the rose garden.
Cuff diplomatically insists on treating everyone equally, breaking down the previous hierarchical divide between the servants (who, under Seegrave, were automatically under suspicion) and the family (who were not). Accordingly, even though Rachel is the purported victim of the crime, she does not get special treatment or evade suspicion.