Throughout her life, high school teacher Park Jagi has possessed the ability to foresee imminent disasters, yet she has never managed to prevent them. One day, she predicts a horrific tragedy at her own school. Unlike her previous nightmares, however, this time she appears within the vision to stop the event, accompanied by three strangers she has not met before. With only a few days left before the catastrophe is set to occur, Jagi is driven to action to alter the future and begins searching for her potential allies. Soon, Jagi meets the mysterious strangers who, like her, have time-related abilities: Kim Young-Tak, a student who can stop time; Chang Sae-Yoon, a narcoleptic woman who can witness incidents 10 minutes before they happen; and Kang Min-Hyuk, a troubled office worker who can rewind time by 10 seconds. Just as she tries to enlist their help, sudden calamity strikes the school. Noting that horrifying incidents have begun occurring earlier than expected, Jagi realizes that she may have misjudged the cause and consequences of her premonition.