Records of the kind translated in Part III above do not emanate immediately from the running of sources/agents/informers, but on their own they nonetheless successfully illuminate crucial aspects of the ‘machinery’ of HUMINT. A history foregrounding such records can convey the broad picture, including of policy changes and the evolution of security agencies as organisations. What has to be kept in mind, however, is that formal doctrine, rules and regulations, and experience written up expressly to document Cold War stakeholders’ views of how HUMINT should be (or, which in this case is no different, should not be) conducted, are not evidence of how it was. Historians eager to get closer to the agent running praxis itself therefore must also interrogate sources of a very different kind, starting with the unevaluated and uninterpreted information produced by the agents and their handlers on the ground. If our interest is in the Cold War FBI, we will find it deposited in bureau files and institutional subfiles on assets as ‘information furnished by the informant’.