This article examines the connections between Thomas Pynchon's V. and the work of W. B. Yeats, arguing that it is not only Yeats as poet, but also Yeats as mage, who interests Pynchon. It shows what part is played in V. by the concepts developed by Yeats in his works Per Amica Silentia Lunae and A Vision - the symbol of interlocking gyres, the twenty-eight phases, the Great Wheel, and the Anima Mundi, or soul of the world. It argues that in the course of the chapter "Confessions of Fausto Maijstral," Pynchon uses the destruction of the Maltese city of Valletta first to both represent and criticize the abstraction of Yeats's Byzantium and second, through the figure of the child poet, to recast Yeats's Anima Mundi as a textual realm open to and changing with the demands and experiences of the present.