As abandoned Mary arrives back at Jamaica Inn, she finds herself in danger.
Mary takes a trip to Launceston with Jem, but it ends unexpectedly.
As Mary's friendship with Jem deepens, her uncle reveals the true nature of his business.
Lost on the moor, Mary is helped by a local vicar who becomes her confidant.
Mary meets her uncle's younger brother Jem Merlyn, and Squire Bassat pays a visit.