Wu Yu is a math major, but works as a mechanic, while Tan Jiao writes mystery novels for a living. The couple meets by accident when Tan Jiao needs to fix her car. However, she has an overwhelming impression that they have met before. Only then, does she realize that she has a year of life completely removed from her memory. Soon, it turns out that the key to her lost memories may be a ship's voyage. The same cruise she and Wu Yu met on. From then on, the couple tries to recreate the course of events from that time, which is even more difficult by the fact that Wu Yu himself has no recollection of time spent on the ship. However, the couple has good reasons to uncover the truth when it turns out that this tour is the key to discovering who murdered Wu Yu's sister. Soon, thanks to the ability to travel in time, both of them are not only trying to recover their memories and save the man's relative, but also to understand why they found themselves in this situation, in the first place. (Source: MyDramaList) ~~ Adapted from the novel "Wu Yun Yu Jiao Yue" (乌云遇皎月) by Ding Mo (丁墨).