Helen has won a place at a prestigious summer music school in remote north-western Scotland. As she practices for a concert on Midsummer's Eve, her friends, the fabled beasts, prepare for battle - in the very forest where the young musicians are staying. When Yann the centaur arrives and warns Helen of impending danger, she is forced to cast her musical ambitions aside. Helen finds herself catapulted into a perilous quest, allied with fantastical creatures against a powerful enemy, the Faery Queen. She finds the mythical island of Tir nan Og, breaks the law and administers first aid to old friends and new . . . but will it be enough to help her friends and save herself?