It's 1947 and London's East End is still a bombed-out landscape. Sister Beatrice, who runs the St Saviour's Children's Home, knows that life is still a precarious existence for many children and it seems that there is no end to the constant stream of waifs and strays who appear at their door looking for a safe haven. One such arrival is Mary Ellen whose mother is gravely ill. The one silver lining is her best friend, the tearaway Billy Baggins, also a resident of the home, but Billy seems intent on falling foul of Sister Beatrice's strict regime. New arrival on the staff, Angela, admires Sister Beatrice, but can see that the children need love and kindness as well as a strong hand. When an unwelcome face from Billy's past arrives on the scene, things are brought to a head.