And One Day They'll Knock is a captivating novel by Louis Sedgwick that tells the story of a girl named Lucy who finds a door leading to a secret world. In this magical place, she meets exceptional and amazing friends with whom she goes on an unforgettable journey. But will she be able to save this world from a terrible threat hanging over it? This book is an exciting journey that will reveal to you the secrets and charm of another world, where faith and friendship become the strongest weapons.