'Crooked Angels' was an investigation on memory's role in performance permanence, sparked by an interest in performance and disappearance. It was part of the collaborative project 'Embodying Ambiguities - Intertextual Plays Within and Between Space/time Philosophies and the Performing Body' (AHRC, Arts Council, Yorkshire Dance and CIDA) directed by Professors Emilyn Claid and Valerie Briginshaw. 'Crooked Angels' advances practice-based research in the area of memory as performative documentation. It situates itself between theoretical discourses of performance's ontology of disappearance, and poststruturalist philosophy. Practically it locates itself in relation to the work of artists whose methodologies of making are also documentation methodologies. The project has developed an understanding of performance as marked by an ontology of permanence. It has developed the notion of ‘performance permanence as memory’ by constructing a documentation modality involving 'the assemblage of performance memories into a document' (Crooked Angels) and a subsequent 'metamorphic tour' of that documentation modality (the tour of Crooked Angels). In so doing, 'Crooked Angels' has pluralised notions of performance permanence and it has related different notions of performance permanence to several different documentation modalities. Whereas most practice-based research exercises distinguish between practical research outputs and documents, because my research's practice is itself concerned with the creation of documents, the research outputs were documents of the work. Moreover, because the research proposes a performative documentation modality, not only were the research outputs documents, but they were also performance works. In other words, the research outputs were both documents (of performance) and performance works themselves.