Spirited Mary Yellan (Jessica Brown Findlay) finds herself alone in the world when her mother passes away. She is forced to move to the isolated Jamaica Inn, deep in the heart of the windswept Cornish moors, where she enters a world where nothing is as it first appears. Joss is the head of a violent smuggling gang and when he isn't smuggling, he is drinking heavily to forget all he has seen and done. Life at Jamaica Inn challenges Mary's black-and-white sense of right and wrong as she finds herself living among smugglers in a lawless land. When she thinks she has witnessed a murder, Mary wonders at what cost she will stay silent.