Based on the Tangshan Earthquake in 1976 which killed more than 200,000 people. Li Yuanni returns home to find out that her 7-year-old twins are buried under the debris. The rescue team explains to her that freeing either child will almost certainly result in the death of the other. Left with this dilemma, she chooses to save her son without knowing that Fang Deng overheard the decision being made. Miraculously, she manages to survive but suffers from the painful memory of her mother's decision...