You get into the science lab for Biology, your first class of the day, and sit down. You're waiting for a few minutes, and there's a bit of a ruckus going on in the class, but then the teacher, Mrs Gray, arrives brandishing a DVD case in her hand. It doesn't have a label or anything, weirdly.
"Sorry I'm late, everyone!" she says. "I've got a meeting in 15 minutes, and I needed to get something set up for you. The lab technicians should be down here in a few minutes with the TV, and then you can watch the DVD I've got planned." Awesome! You won't have to do any work today! "You don't need to take notes on it, but you'll probably finding yourself paying attention, let me put it that way," she grins.
The technicians come in with the TV and plug it in, and after sending them out, she puts in the DVD. It's something recorded off the TV, it seems like. Once she's pressed Play, she slips out, turns off the lights and locks the door.
You were expecting to be able to bunk off this class, but you- and everyone else in class- are indeed gonna be paying close attention.