Send in the cavalry

"Classically," said Leslie daFox, "the four horsemen of the Apocalypse are considered to be metaphors.  Each is the personfication of a human condition, and if you were only cleverer I would call this anthropomorphisation and relate it back to the third series of How I murdered your mother, the sitcom I won my first thirty awards for writing."  He looked around the room, hoping against hope that there would be a spark of recognition, if not for what he was saying then at least for the comedy show he'd written single-handedly (and two-fingeredly) for four seasons before the network had given him a staff of writers, a bigger salary, and an ulcer.  Instead there were blank faces (most of the first two rows, all women, all the wrong side of middle age, and judging from their homework, all writers of Harry Potter slash fiction), confused faces (generally people on the edges of the class, though he now knew that Mr. Harrison was just in denial about his deafness), worried faces (mostly students who needed to pass this course as part of their degree program and were scared it was too much like work) and dead faces.
"Can anyone name another example of anthropomorphisation?" he asked wearily.  A door creaked, and he saw one of the Camberwick Green security guards sidling in at the back, clutching a clipboard defensively to his chest.  Leslie felt slightly relieved that he'd managed to ask the question before the guard had arrived, as the guards here were actually very good at answering them, which upset the audience even more.
"No?"  Leslie scanned the faces of the audience, suddenly aware that his mental catalogue last time had included an item that had been wrong.  Let's see, he had the blank faces, the worried faces– a hand had been raised.
"YES?" he shouted, but the room was large and no-one here seemed cowed by it.
"Er, SpongeBob Squarepants?" said a thin man with a pointed nose and rheumy eyes.  His lips were pale and thin, as though he spent a lot of time compressing them tightly against one another.
–worried faces, confused faces– what?
"What?" he said.
"SpongeBob Squarepants.  You know, he lives in a pineapple... under... the sea."  The young man trailed off while Leslie realised that he'd seen the cartoon creation that was being referred to when his grandchildren had come to visit.
"I... Well...," Leslie tried to figure how to say no, given that the answer was actually yes.
–confused faces, dead faces.   Wait, what?
"What?"  He scanned the audience again, and sure enough, there in the middle were two elderly women with blue-grey faces that looked very dead.  "Can someone wake er, thingy, there, in the middle?"  He pointed, and slowly, reluctantly, a neighbour gently shook one of the dead women.  They wobbled a little, and then keeled over, faceplanting the desk in front of them, and revealing a plastic-handled knife sticking out of a large bloodstain in the shirt on their back.  There was a scream, a pause while the room worked out what was happening, and then more screams.
The security guard hurried forward, and Leslie noticed that the skinny young man had put his hand back up and was waving it back and forth with more enthusiasm than anyone had managed in any class previously.
"Yes?" he said, watching as the security guard tried to find a pulse on a corpse.
"Am I right?  About SpongeBob, I mean?"
Leslie nodded, aware that since no-one else was paying any attention he could deny it later.  The security guard had just sat the corpse back up, driving the knife further into its back by the look of things.
"Cool, dude!" said the skinny guy, and turned to his neighbour, presumably to boast about his intellectual capacity.
"I think this one's dead," said the security guard, now dragging the corpse up onto his shoulders.  "I'll just take it out back and tidy it up a little.  We'll need to talk to you later about how it happened."
"What?  How what happened?"
"Well, it's a locked room mystery, isn't it?" said the guard sounding suspiciously happy.  "Like in one of your books.  So it's a test, isn't it, right?"
"No," said Leslie, who'd never written any crime fiction in his life.  "And no, and more no.  That's a dead body, and I don't know how it got in here, but I'd like it taken away and identified.  And crossed off my class-list."
"Right you are, sir," said the guard, winking when he thought only Leslie could see.  "Jolly good!"
"Did that... thing die in here?  While we were in here?"  The speaker, a young girl, looked ghoulishly thrilled, and several of her classmates started jotting things down in their commonplace books.
"Bravo!" said Leslie, suddenly proud of his class for the first time since he'd started teaching again.  "Every event that happens, no matter how tragic, or personally affecting, can be used as the plot for a story, or even just background material.  Now, who can tell me about corpse worms?"
The fastest hand up was the woman whose last Harry Potter fiction had featured some fairly graphic necromancy, so Leslie picked someone else instead.