On Christmas Eve, Jean Martens (Pierre Blanchar), a Swiss minister, takes in a blind half-crippled orphan and brings her up with his four children. But Gertrude (Michèle Morgan) grows to be a woman and Jean gradually falls in love with her without admitting it to himself. On the contrary, he lulls his conscience by interpreting the Scriptures to his advantage. But neither his wife nor his oldest son are fooled. When, after a long-delayed operation, Gertrude recovers her sight she is not long to find out that sin has corrupted the soul of her benefactor. Seeing no hope in the situation, the young woman decides to take her own life.