CSDIC is best known for the transcripts of prisoner conversations it generated through covert listening. Yet these dialogues stand largely on their own: they contain no material to explain why particular prisoners and conversations were monitored. The chapter argues that to understand the purpose of these transcripts, we need to look beyond them, to the other kinds of reports CSDIC produced that were not derived from microphones. Numbering roughly 2,500 documents, these reports chart a transformation in the information Britain sought to extract from these prisoners. The chapter shows how CSDIC was initially concerned with military information, but that it soon expanded in both reach and ambition, moving from tactical and operational intelligence to more specialised studies aimed at understanding enemy morale and shaping post-war occupation planning. Alongside these efforts, its microphones were also capturing references to atrocities and a growing awareness among some soldiers of the genocidal intent behind them. Yet such revelations remained subordinate to institutional priorities about protecting CSDIC’s methods even after 1945.