In the future, Earth itself is no longer inhabitable by living creatures. Humans begin their interstellar migration with space colonies. Vince and Hana work as researchers in the Cambrian Project. Together with the creature Pikaia, they seek the Lost Code, the key to restoring Earth, and aim to return to Cambrian-era Earth.
Ye Daji meets an old classmate, Ming, who asks him out for coffee but makes him pay for a big meal instead. When a vagabond walks in and is chased away by the restaurant manager, Daji speaks up for him and even gives him a treat. Daji is sad when his girlfriend, Jiexi, turns down his marriage proposal again. Ye Da is a divorcee with a 10-year-old son, Xie Tingfeng. She lives with Daji and teaches martial arts for a living. As she has few students, Daji tries to stage fights to show off her skills.