One hot summer day in 2003, 40-year-old art historian Melike Isik she leaves her summer home in Princes Island and takes the ferry to Fener, one of the oldest neighbourhoods in the city.

She is travelling to a mysterious meeting with an even more mysterious man. Known only to her through a brief email exchange, Petros has contacted her out of the blue, asking for a tour of Istanbul's Byzantine churches. Melike, intrigued, agrees to help.

The place they arrange to meet, the Church of Saint Mary of Mongols, holds tender memories for Melike, located right across from where her long-dead grandmother lies. But what Melike at first assumes is a coincidence soon gives way to something much greater.

And as she begins to realise Petros's real motivations, long-held secrets begin to unravel…