Pascali’s Island, by Barry Unsworth

In the waning days of the Ottoman Empire, Basil Pascali has drawn a small salary from the Sultan for the last 20 years in return for sending reports of suspicious activities on the island where he lives. Nisi is a fictional Greek island occupied by the Turks. However, the Sultan's machinery of empire has grown so complex—byzantine, indeed—and his network of informers so vast, that Pascali's efforts go unacknowledged, perhaps even unread.

Except by us. The book is a series of reports to the Sul...