A correspondence begins between Juliet Ashton (Lily James) and members of The Guernsey Literary and Potato Peel Pie Society, with them sharing their experiences of Nazi-occupied Guernsey Island. When an idea for a book catches Juliet, she goes to visit the island, making life-long friends and taking life changing steps along the way. This book is told by way of letters, and as the reader, you become enchanted by the writers of them and the love Juliet comes to feel for each of the Islanders; Dawsey Adams (Michiel Huisman), Amelia Maugery (Dame Penelope Wilton), Isola Pribby (Katherine Parkinson), Eben Ramsey (Sir Tom Courtenay), Kit (Florence Keen), and Elizabeth McKenna (Jessica Brown Findlay).