The Fantomaya are three old women who dwell on Odom's Spire, the 25th Hour. They are Diamanda, an old wise-woman; Joephi, who subtly appears feral; and Mespa, who is dark-skinned and has eyes the color of the night sky. They are very mysterious, and little is known about them, other than the implication that they have a power, that they constantly study and protect the history of the universe.

Diamanda is revealed eventually to have been an ordinary woman dwelling in Chickentown (then called "Murkitt" after her husband's ancestors), who left the human world and joined the sisterhood some time after her marriage. This may mean that the Fantomaya are mortals who have chosen their positions voluntarily and have been changed in the process. Diamanda's mortality is confirmed by her death on the isle of Efreet by a Sanguinius as she tries to save Candy.