He lives in other people's countdown, counting death and redemption second by second. Lin Ye, a former surgeon, is now a substitute who can see the countdown of a person's life, and is forced to enter a rich and powerful family to replace the missing heir. When he desperately saves people and repairs his false identity, he discovers that behind every timer there are cloning and powerful hands. The pursuit of power, family mysteries, and ethical trials are approaching in turn. His true identity is more dangerous than he imagined, and he is closer to redemption. Must he risk his life to uncover the truth before the countdown ends, or continue to be that gentle substitute? Every time he counts down, it's like asking him: What is home? The choice of blood and love is intertwined.