A spellbinding love story, Castle Dor was the unfinished last novel of the British novelist Sir Arthur Quiller-Couch, better known as "Q." The novel was passed on to Daphne du Maurier by his daughter, who was sure that du Maurier's storytelling skills were perfectly suited to completing the tale.

The result is a magical, compelling retelling of Tristan and Iseult, the star-crossed lovers transplanted in time to the Cornwall of the last century. A chance encounter between the Breton onion-seller, Amyot Trestane, and the newly-wed Linnet Lewarne launches their tragic story, taking them in the fateful footsteps of the doomed lovers of Cornish legend.