“Remember,” I told them. “You have a week to get late homework to me. Anything later than that falls into the abyss.”
I drew a picture. I attached it to the message. In class the next day, I taped it up in the front of the room.
“What’s this?” I asked the students.
“The abyss,” someone said.
From this, and from the flood of late homework that arrived over the next few days, I think it’s fair to say they got the message.