From the author of The Magician's Daughter comes a historical fantasy where dreams come to life and Arthurian legends are reborn, perfect for fans of The Everlasting and The Once and Future King. 
Wales, 1941. As war rages across the globe and bombs fall from the sky, people all over the world begin to dream of King Arthur. The dreams spread like a fantastical plague, flooding people's sleep night after night. Whispers arise of wonders and unexplained sights—dragons in the London Underground, and strange lights over Stonehenge. Self-proclaimed prophets claim they are miracles, heralding Arthur's return at the time of Britain's greatest need.
Elaine Ambrose has never dreamed of Arthur, and she doesn't believe in miracles. A librarian at the British Museum, she wants only to protect the museum's collection from the London Blitz, and is frustrated to be sent instead to catalogue a reclusive professor's private library on the coast of North Wales. But all is not as it seems. Soon Ellie must confront what she's tried to ignore: she dreams not of Arthur, but of Nimue—the Lady of the Lake. And her dreams promise not salvation, but a return to the darkness of the last days of Camelot.