It's 1946 and Juliet Ashton can't think what to write next. Out of the blue, she receives a letter from Dawsey Adams of Guernsey - by chance, he's acquired a book that once belonged to her - and, spurred on by their mutual love of reading, they begin a correspondence. When Dawsey reveals that he is a member of the Guernsey Literary and Potato Peel Pie Society, her curiosity is piqued and it's not long before she begins to hear from other members....