In order to save his lover who died in a car accident, he used a time pocket watch to reverse his fate 30,000 times, but became a prisoner of time in reincarnation. When she discovered the truth, she could only use her own heartbeat as an anchor to reverse time and space, and use a synchronization of life and death across dimensions to fight against the laws of the universe.
Concept: The greatest invention of mankind is not the time machine, but the courage to choose to love each other even though you know the outcome.