But when the great novelist, Sir Arthur Conan Doyle, endorses the photographs' authenticity, the girls become a sensation; their discovery offering something to believe in amid a world ravaged by war.

One hundred years later... When Olivia Kavanagh finds an old manuscript and a photograph in her late grandfather's bookshop she becomes fascinated by the story of the two young girls who mystified the world. As Olivia is drawn into events a century ago, she becomes aware of the past and the present intertwining, blurring her understanding of what is real and what is imagined.

As she begins to understand why a nation once believed in fairies, will Olivia find a way to believe in herself?