In the 1960s, a old woman, her son, and her daughter-in-law host guests for Sunday lunch. The woman thinks she has kept the nuclear shelter beneath the house secret from her son, with whom she has a strained relationship. However, her son knows and has installed a back way in, such that he can surprise her there after she locks herself inside.

After World War II, as he skis in the mountains of Switzerland, a Jewish Frenchman recognizes a German man who once left him for dead in the snow as a child.