Lydia Carlton is a fairy doctor, one of the few people with the ability to see the magical creatures who share our world. During one of her rare trips to London to visit her father, Lydia's quiet life is suddenly transformed when she is rescued from kidnappers by a mysterious young man!

Edgar Ashenbert claims to be descended from the human ruler of the fairy kingdom, and he urgently needs Lydia's help to find and claim his birthright, the legendary sword of the Blue Knight Earl. Things will never be the same for Lydia as she is pulled into a dangerous quest against dark forces!