Opening with an anecdote about Synge’s attempts at telepathy, and using much archival material, this chapter reveals Synge’s engagement with occultism, showing it to be not only pervasive but integral to his work. Although Synge as occultist has never been granted credence in studies of the writer, he read widely in occult literature, covering theosophy, magic, telepathy, and other pseudosciences. This reading coincided with Synge’s engagement with socialism, and the two interests were closely linked. Focusing principally on Synge’s major prose work The Aran Islands (1907), the chapter draws on numerous drafts, along with Synge’s ‘Autobiography’ and ‘Étude Morbide’, to show that Synge made recourse to occult mysticism in response to moments of fragmentation, where modernity becomes most pressing and disruptive. In this way, the first chapter introduces Synge as a mystical thinker and a leftist writer whose works were a nuanced and self-reflexive reaction to modernity. It also introduces the key methodology of the book as a whole, mobilizing Synge’s archives and reading diaries, and bringing to light new source materials in order to illuminate the processes of influence and authorial revision at work behind his texts. Using works by Madame Blavatsky, Maurice Maeterlinck, Annie Besant, William Morris, W. B. Yeats, Laurence Oliphant, and others, this chapter places Synge back into the context of fin de siècle occultism, and in doing so reveals the roots of his synthesis of mystic and political thought.