In 1917, two young Yorkshire cousins, Frances Griffiths and Elsie Wright, announce they've photographed actual fairies living in their Cottingley, England, garden. The photos are declared real by none other than Sir Arthur Conan Doyle, and a nation torn apart by tragedy embraces this amazing event. The cousins keep their secret about the photos for decades, until they decide it's time to tell the truth. One hundred years later, Olivia Kavanagh inherits her grandfather's bookshop, and is amazed to find a manuscript that has been hidden away for decades. She becomes fascinated by the tale it tells. But it's the discovery of an old photograph that leads her to realize how the story of Frances and Elsie intertwines with hers, connecting past to present, and blurring what is real and what is imagined.