When Horla’s best friend Carar moves to another town, she wishes for a new friend, one that comesfrom a parallel world to Ivarnio, a parallel world where she becomes invisible and has specialpowers... A parallel world called Earth.

On Earth, Lucy sits sad and lonely in her bedroom, having waved off her own best friend Eleanor fora new life in Liverpool. Suddenly, Horla’s face appears in Lucy’s dressing table mirror, and quickly aunique friendship is formed.

Getting up to all kinds of mischief that baffles children and adults alike, together they are the perfectpair. That is, until, Eleanor says she misses Lucy terribly and begs to see her. Soaring up into the sky,Horla and Lucy set off on an adventure to meet her, and when Horla tries to help her make newfriends, Eleanor is set the challenge of carrying out a very dangerous rescue; a rescue no other childwould ever dare to attempt...