William Devonshire Saull was a financial kingpin of the political underworld. His wine-trade profits were as essential to the deist-cum-atheist Richard Carlile’s anti-clerical movement in the 1820s as to Robert Owen’s socialism in the 1830s. And Saull’s museum of fossils—forgotten today—was designed to glorify an evolutionary world with its promise of earthly salvation for the downtrodden. This opening section explains why the new understandings of earth history were paramount in the blasphemy/socialist movements, as it sought to shrug off clerical and capitalist control. It details some of the new, untapped sources for dealing with the subject at street level: police spy reports, the newly-digitized London newspapers, and satirical magazines, which left a wide class of readers laughing at Saull’s belief in a monkey ancestry for mankind. The introduction also touches on Victorian sensitivities to explain why Saull, his bankrolling activities and criminal enormities (atheism, socialism, evolution), are so little known. It gives a preview of Saull’s political activities: in London’s first Labour Exchange, in rational schooling experiments, in his materialism as a seditious, anti-theological weapon, and in his help for the emerging working-class activists resisting tithes and clerical oppression. ‘Atheism’ was never a stationary concept, and we track its changes as activists developed new vectors of attack. Science’s multiplicity of meanings for the underclass is also explored. The theme of this section is Saull’s gigantic, free-to-all museum and why it has escaped attention, and how we have to refocus to see it in its true dissident context.