In March 1637, the galleasses of the Venetian Mediterranean fleet docked in the port of the small island of Milos in the Cyclades. While there, a widow and her three daughters were spirited onto the great galley of the fleet commander, and fled the island for the Venetian stronghold of Corfu. These were far from normal passengers, however. The mother was the widow of the a?a of Milos, and the oldest daughter, Aisss ,was married to Mustafa Effendi, the island's kadi. Despite her elevated status, however, it was ultimately serious dissatisfaction in AissA's marital relationship that precipitated the women's flight. Based on archival sources in Venice, Rome and Greece, as well as Ottoman chronicles, this case opens a window onto the under-studied phenomenon of conversion and apostasy among Muslim women in the early modern Mediterranean. In this paper I will use Aiss 's experience as a window onto the fluidity of Mediterranean women's religious identity, and the ways in which they used the spaces of the sea, as well as its political and religious boundaries as a means of asserting agency.