This talk is the story of an Irish émigré with a dark secret, in London, 1888. Against a backdrop of resistance/sedition, assassins, secret societies, informers and spies, we will hear voices hidden for a century in a tale of family betrayal and comrades turned one against another, and the beginnings of modern internal state security and witness protection. Recent landmark decisions of the Information Commissioner (2011-2015) have sealed records of these events effectively indefinitely, despite their now being 130 years old – to protect today’s information-gathering methods, and present-day descendants of 1880s informants – leading us to ask where the limits of access to historical source material should lie.