During the Tianbao period of the Tang Dynasty, Li Shande, a petty official in Chang'an, was suddenly given a task to bring fresh lychees from Lingnan. The lychee is perishable, and becomes tasteless three days after it leaves the branch, and Lingnan is more than 5,000 miles away from Chang'an, so this is an impossible task. But for the sake of his wife and daughter at home, Li Shande was determined to give it a try.
In the 1940s, the world was in turmoil, and it was crucial to decipher the enemy's communication codes in a timely and accurate manner. Rong Jinzhen has shown amazing mathematical talent since her childhood, and because she solved the problems assigned by her math teacher, she was noticed by more people, and even walked into the door of code-breaking by mistake.
An exploratory dive into the deepest depths of the ocean of a daring research team spirals into chaos when a malevolent mining operation threatens their mission and forces them into a high-stakes battle for survival.