'A smile costs nothing, but gives so much'. With one short poem, French writer and humanitarian Raoul Follereau spoke to the world about the value of this fundamentally human expression. Since 1920 'A Smile' has been translated into many languages around the world. In this first presentation in a children's book, the poignant words accompany an intergenerational story in pictures about two children, and the many lives affected by their infectious smiles. A dejected street musician. A lonely businessman. An exhausted teacher. All are uplifted by the generosity, compassion and friendship inspired by a simple smile. Created in paper collage by internationally award-winning illustrator Hoda Hadadi, the illustrations burst with joyful emotions that will impact the hearts of every reader. Although Raoul Follereau passed away in 1977, his belief in the ability of children to change the world shines through in this book. A closing note shares details about Follereau's work: his thirty years travelling the world with his equally committed wife, to give aid to and raise awareness for people with leprosy, and his creation of World Leprosy Day, which is still marked on the last Sunday in January every year. The Raoul Follereau Foundation in Paris, and 14 associations around the world, continue his humanitarian work.