The accountant Che-ah feels bored in her routined life, when one day she dies mysteriously at 6pm. Waking up to the same day, May 25th, she discovers she's in a time loop with 6pm as the turnover point. Though she enjoys it at first, she soon realizes an escape won't be easy. The producer Jihoon tells her "I know what's happening…". Can she escape the time loop and go home?
