The Perishing of the Pendragons (The Father Brown Classics, Episode 20)

"The Perishing of the Pendragons" by G.K. Chesterton is a Father Brown story where Father Brown is invited on a boat trip around the Cornish coast, where he encounters a family called the Pendragons, who are plagued by a mysterious curse tied to a local legend about a Spanish prisoner and a treacherous coastline...