One Way Out

You waited for Emma to finish drinking from the fountain. She stayed a little longer than you expected, kicking at the lockers and opening some. You watched, bored, as she raided the open lockers. Out of nowhere, a knife whizzed past you and struck Emma in the leg. She went down and glanced around, looking for her attacker. You looked around as well. There was no one in sight. Emma shook her head and muttered under her breath, then proceeded to stand up. She couldn't. She was vulnerable and she knew well enough what this place did to vulnerable people.
She started crawling towards the closest door, which happened to be the janitor's closet. She closed the door behind her. You heard distant footsteps behind you and you turned. It was John.