What is That Beeping Sound?

Edgar just wanted to go to sleep, but the flimsy hotel walls were not blocking any noise.  He thought about complaining to the front desk, but didn’t want to draw attention to himself.  Besides, it just sounded like an alarm clock. 

If it was an alarm clock, it had been going off for almost an hour.  He couldn’t take it any more, and went next door to tell them off.  He knocked and the door opened, like it wasn’t latched.  He waited for a few seconds. 

“Is anyone in here?” Edgar entered, and saw a prostrate body on the bed.