The opening sequence follows a victim who is stalked by her boyfriend's jealous brother while running through a field. As she runs, the stalker watches her from a hidden location. She finds a necklace on the ground that triggers a flashback, revealing the stalker had been in her school changing room. Though she sees no one around, the stalker begins following her closer as she enters the nearby woods. The sequence establishes the victim, location, and introduces the mysterious stalker character and builds tension through music and camerawork.