Quiet office worker Lason witnesses a vicious alleyway homicide on Christmas Eve, only for detectives to brand him mentally unstable when physical proof evaporates. The nightmare escalates when his girlfriend and her household are slaughtered by an elusive executioner who anticipates Lason's every move with eerie familiarity.
Driven to the brink of despair, Lason discovers a battered vintage phone capable of rewinding temporal cycles by several hours. As he loops through recurring death traps to shield his loved ones, he unmasks a smiling senior coworker who has exploited temporal resets for decades, forcing a fatal duel across splintering timelines.
