You manage to stammer out, "Uh, I've got another class right now."
She sticks her lower lip out in a pout. "Oh, fuck, it's only first period. Well, drop by at the end of the day. I'm sure I'll be happy to see you." She slowly licks her lips.
You get up and head for the classroom door. A couple of students have already arrived for second period, but don't seem to have any reaction to the unfamiliar teacher at the front of the room.
Out in the hallway, you walk quickly to get to your second period class, on the opposite end of the school. As you round the corner into the English wing, suddenly the buzz of conversation in the hall quiets, and everyone just stops, frozen.
Your friend Keith is nearby, motionless, looking as if he's about to take a step. "Keith, what's going on?" you ask. No response. You tap him on the elbow. Nothing. You shove his upper arm -- it's like shoving a statue. "What's going on here?" you practically shriek to no one in particular.
A voice comes from behind you. "I've stopped time."