We see multiple shots of the locker room. From one of the lockers, we hear loud banging, kicking against metal to be precise.
Scene 6 (M)
GEMMA LAMPHERE gets out of one of the lockers. She is panting and coughing from the lack of oxygen in there.
GEMMA walks to the door leading outside, slightly gimping from staying in the same position for hours in a tight space. The door is locked, she wasn't expecting it.
She hears noises coming from the hallway and sees the school's JANITOR, JOSEPHINE. JOSEPHINE is just walking around, she doesn't seem occupied at all. GEMMA sighs at the JANITOR because she wants to help.