1275... a cry for help from a woman who is kidnapped at sea. 2016. Dutch archivist Fenna van Wijk is helping architect Ned Thompson sifting through a stack of ancient papers kept in an untouched archive in an old English manor house in Lincolnshire. Among manuscripts dealing with the holy Gilbert of Sempringham, they discover a letter from 1275, written by Eleanor de Montfort, the young bride to be of Welsh prince Llywelyn ap Gruffudd. During their research, Fenna stumbles upon Eleanor's only child: Gwenllian. The English king Edward I had his enemy's infant locked away for ever in a cloister in... Sempringham. When Fenna and Ned try to understand this harsh decision, they find more than they bargained for.