Nechama Tec wrote the important analysis of Christian rescue in Poland "When Light Pierced the Darkness". This book is her own story.
Nechama Bawnik was 8 when the Nazis forced her family into hiding. The family hid with a Polish Christian household which for payment provided them with protection. They lived in constant fear of betrayal. Roman, the father, was resourceful and saved them many times over.
Necham became an adult quickly. As a child and thus below suspicion she became the family salesperson. She sold their baked goods on the black market. After liberation their ties to their Polish rescuers dissolved in a few months because of the fear that the Polish family had that their Polish neighbors would disapprove of saving Jews.