The worlds of Central Asia and the Indian Ocean have been seen as discrete, seemingly unconnected except by way of the vertical silk roads descending through feeder routes into port cities situated along the Indian Ocean and its many seas, gulfs, and bays. Before Central Asia lost historical centrality and was regarded increasingly as a blank space on the map, it was a dynamic region. The Indian Ocean world with its spice, cotton, and silk routes was more known, having entered European geographical knowledge - and fantasy - from antiquity. The two worlds - terrestrial and oceanic - have been seen as diametrically opposed, with historiography privileging the latter. This essay links the two worlds by evoking people, places, and mobility through the legend of Prester John, a mysterious Christian monarch and putative ally against Muslims.