Castle Dor began life as the unfinished last novel by Sir Arthur Quiller-Couch, the celebrated 'Q', and was passed by his daughter to Daphne du Maurier. The story is based around the legend of Tristan and Iseult, but set in 19th century Cornwall. The main characters are a Bretononion seller, called Amyot Trestane, and the newly-wed Linnet Lewarne.