The old lady's husband was actually her young lover.

On the day of the substitute marriage, as the second young lady of the Song family was to be married, the eldest young lady, who had supposedly died, miraculously came back to life, shocking the entire city. In reality, the eldest young lady had already passed away; the one who had returned was Song Yan, the Song family's ancestor who had cultivated immortality for a thousand years. She had descended the mountain this time only to undergo a tribulation to repay a debt of love, and the debtor was none other than the eldest young lady's fiancé—Qiao Sijing, the young master of Song City's most powerful family. Qiao Sijing was handsome and extraordinary, but cold and aloof. Due to a marriage agreement with the Song family, he was unwilling but still had to marry the originally weak and incompetent eldest young lady. Little did he know that he harbored deep resentment towards Song Yan, all because he had been hurt by her in a past life.