Although common within media and cultural studies, fan studies approaches are more rarely applied to theatre. Drawing on the author's exclusive access to Punchdrunk's archives, this chapter considers audience communication during Punchdrunk's Faust (2006) and The Masque of the Red Death (2007), and the development of international Punchdrunk fan communities around Sleep No More (2011–) and The Drowned Man (2013–2014), to argue that audience participation or fan activity is itself a form of interactivity with immersive theatre. Biggin identifies themes and vocabularies across Punchdrunk fan discourse, proposing that fan activity includes the active production of further texts. The chapter concludes that fan interactivity is a means of claiming ownership over immersive experience and expressing relationships with Punchdrunk productions beyond the moment of theatrical encounter.