One winter night in Prague, Helen Franklin meets her friend Karel on the street.

Agitated and enthralled, he tells her he has come into possession of a mysterious old manuscript, filled with personal testimonies that take them from 17th-century England to wartime Czechoslovakia, the tropical streets of Manila, and 1920s Turkey. All of them tell of being followed by a tall, silent woman in black, bearing an unforgettable message.

Helen reads its contents with intrigue, but everything in her life is about to change.