Sadullah Efendi is a Sufi leader in Constantinople and the immediate religious guide of Gizem Faruki — the figure who stands to her, in the ordering of her faith, much as a local imam or priest would, where her old mentor Anna served rather as a one-to-one master of the inward path. He is a mild-mannered man, unhurried and soft of speech, and it is precisely that gentleness that disarms: he makes no incendiary pronouncements and courts no reputation as a radical, yet the theology beneath his kindness is quietly revolutionary, ecumenical to a degree that would trouble the authorities were they to piece it together — reaching across Shia, Sunni, and Orthodox alike toward the ground they hold in common. His views run close to Gizem's own, which is why she counts herself of his community.
He came to the company's notice when Gizem, choosing between him and Anna, brought him the Ghost of March's invitation to the Grand Negotiation. He would attend, he said, and make the case for mutual respect — but he would pledge his congregation to nothing and take no part in treason, and would excuse himself before any plot was hatched. At the table he kept that word exactly: he stood to plead that no deed be done in a people's name that the people must then answer for, that difference in worship and in life be met with resilience rather than reprisal, and then he withdrew with the company before the room could turn to conspiracy. A man, in short, of a deft and dangerous conscience — the sort whose plainest words carry the furthest.