In the near future, the human federation faces a devastating invasion by the mysterious alien race "Reapers". Qin Zhan, the youngest fleet commander in the Federation, received help from a mysterious girl Lin Xingyue in a desperate situation. She not only mastered the enemy's weaknesses, but also revealed the core secret of the rift in time and space - she came from the future and witnessed the end of human civilization. As the cooperation between the two deepens, they discover that the Reapers are not an alien race, but the descendants of future humans; the top federal officials have long been infiltrated, and there are conspiracies and betrayals across time hidden behind the cracks in time and space. As a "key", Lin Xingyue is responsible for saving multiple timelines, while Qin Zhan is her constant "anchor" in countless time loops. Under the multiple attacks of time reset, parallel universes, ancient consciousness and cosmic existence, they must break the cycle of fate and find the final answer to the coexistence of human beings and the universe.
