Returning from a long trip abroad, Jun-young, a skilled doctor, comes across a car accident scene on the way to meet his daughter. It turns out that the dead hit by a taxi is none other than his beloved daughter, Eun-jung.
Then suddenly, everything repeats like a déjà vu: Eun-jung getting hit by a taxi and Min-chul, the paramedic, checking on other victims including his own wife inside the taxi.
The disastrous hours repeat yet again: the accident scene, Eun-jung, Min-chul’s desperate face, and so on. Lost in repetition, Jun-young notices that he is not the only one trying to save a loved one in the endless time loop. Now, Jun-young and Min-chul decide to work together to redesign the gruesome future.