An ambitious contribution to ‘critical citizenship studies’ – where the author herself places the work alongside the oeuvre of Étienne Balibar, Engin Isin and RBJ Walker, the book’s main intellectual influences – shifting our thinking back to the ontological foundations of ‘citizen’ … the book will have achieved its highest aim if all those working on migration and citizenship from various disciplinary perspectives take account of and engage with the challenge of understanding ‘ambiguous’ forms of citizenship.