"Love Letters from Time: Lu Yao Knows Mary" tells the romantic story of Lu Yao and Mary, who met, got to know each other, and fell in love in college, through graduation choices, tests in different places, and growing up together, to getting married, and then encountered a crisis of trust and emotional ups and downs after marriage, and finally stuck to their love on the edge of life and death.
Lu Yao fell in love with Mary at first sight on the first day of college. From then on, he guarded her silently and the two gradually got closer. Lu Yao refused to give up even after his confession was rejected. Mary also made it clear about her feelings while getting along, and the two confirmed their relationship. After graduating from college, Lu Yao went abroad for further study, and Mary worked in China. Although they were thousands of miles apart, their relationship became deeper and deeper through contact and gathering.
After returning to China, Lu Yao's proposal was successful and the two got engaged and prepared for the wedding together. However, due to Lu Yao's past and his entanglement with Xiaoyan, the wedding had twists and turns. Mary left sadly, but she finally chose to forgive and the wedding went smoothly. Married life is sweet and Mary is pregnant. However, Xiaoyan reappears, triggering a new crisis. Mary is heartbroken after discovering the connection between Lu Yao and Xiaoyan. Lu Yao tries his best to save her. Mary decides to give the marriage another chance after traveling to a small town.
Because Xiaoyan was jealous of Lu Yao and Mary's happy life, she reunited with Lin Yu in the company. In order to pursue Xiaoyan, Lin Yu stumbling upon Lu Yao at work, isolating him, monitoring Lu Yao and Xiaoyan, and instigating their relationship with Mary. During the team building party, Lin Yu even poisoned Lu Yao and made him unconscious. Mary and Xiaoyan stayed in the hospital waiting for a miracle, while Lin Yu struggled with fear and self-blame. The story moved towards the unknown amid the uncertainty of Lu Yao's life and death and the complex emotions of everyone, showing the twists and turns and tenacity of love under the test of reality.