Rowan's mother went missing seven years ago, and now, her father is grieving and her little sister is growing up fast. One summer day Rowan escapes to the place she remembers visiting with her mother: Hyde Park, in the very heart of London.
There, she sits beneath a weeping beech and cries herself to sleep. Her tears open a portal into a world of fairy clans she never knew existed, fighting off wild foxes and even greater enemies. Rowan herself is magically transformed, but is determined to get home to the only family she has left.
Then she discovers that someone very special is trapped in the same fairy world. Can Rowan save the mother she never wanted to lose, and get them both back to where they belong?