Typical works on the Trinity such as, say, Robert Letham's (2020), survey the biblical foundations of the doctrine, the history of its development and accompanying issues. Sonderegger will have none of that. She writes with a poetic almost hortatory prose (reminiscent of Barth), displaying a deep awareness of the theological landscape and of modern philosophy (e.g., Kant, Hegel, Descartes) as well as a willingness to challenge the contemporary consensus in Trinitarian theology. In a word, Sonderegger's Trinitarian theology is like no other. Deeply concerned to maintain the, as she terms it, 'unicity' of God (in line with vol 1 of her ST), she argues that the processions of God (generation, spiration) precede the persons of God, with the latter reduplicating and thus completing the former. The reader's patience will be stretched at times as the author adventures into lands seemingly disconnected from the doctrine in view; but persistent will be paid with reward. I am convinced that this will be a book that will need to be wrestled with and fought through for those seriously interested in the depths and complexities that is the doctrine of the Trinity.