A marriage letter binds forensic doctor Jian Lingwei and director Huo Langsheng as husband and wife. When an epidemic broke out on the cruise ship returning home, she used a scalpel to trace the source and track down the culprit, while he used logic as a network to lock in the behind-the-scenes situation. They were married by contract, and the agreement was for one year, but his family, country, and world later became hers.
