In my dark, dark walk-in stock cupboard is a dark, dark shelf, and on that dark, dark shelf is a dark, dark cardboard box, and in that dark, dark cardboard box is ... OH MY GOD.

I stifle a scream, but only for as long as it takes me to step backwards into the space where the floor would have been had I not been standing on a chair. Contrary to popular belief, the fall doesn’t happen in slow motion and I don’t see my entire life pass before my eyes. Instead I get a split second to contemplate what sort of a landing I can expect before making the one I don’t expect. Fortunately it involves a bag of PE balls being in the wrong place at the right time.

Mind you, my relief is short-lived because I notice that the offending cardboard box has fallen with me and spilled its gruesome contents too close for comfort. Now it is impossible to ignore. No longer can I convince myself that I imagined the whole thing. The earthly remains of a black cat are right in front of me. Frozen by rigor mortis in that curled position cats like to lie in while occupying a sunny window ledge, a comfortable chair or, in this case, all eternity.

This is the first time since I started teaching - halfway through the last ice age - that I have job-shared with anyone. My classroom has always been my personal domain. I like my displays to be slightly wonky, OK? I keep the clock five minutes fast for psychological reasons, all right? My filing systems are meant to be beyond mortal comprehension, otherwise how would I keep the head in a state of confusion?

But from now on I must share my domain - including the stock cupboard - with someone else; apparently the sort of someone else who stores dead cats in cardboard boxes. Don’t get me wrong, I’m sure Morticia is a lovely person once you get to know her, and any rumours I might have accidentally started about possible links to witchcraft and the dark arts are most likely exaggerated.

The problem is that although I share the same space as my job-share partner, I don’t share it at the same time. When Morticia is at school I’m at home, and when I’m at school she is probably hanging upside down in a darkened belfry. We seldom see each other during the hours of daylight and communication is restricted to emails, Post-its and the spirit world. And in my experience, a Ouija board is not the best way to tell your colleague that the lesson on adverbial clauses went well, Ryan still can’t subtract two-digit numbers on a number line, Rebecca moved to blue reading level and, by the way, why is there a dead moggy in the stock cupboard?

It’s not every day that I’m required to poke anything as stiff and hairy as this, but I eventually pluck up the courage to do what a man’s got to do. Now the truth is at last revealed, and what I thought was real turns out to be merely realistic. The cat is just a very good fake, right down to the baleful stare, the dilapidated fur and a vague smell of dead fish.

I suspect that at one time it looked quite homely lying motionless on the rug in front of Morticia’s flame-effect cauldron. All the benefits of a real cat without the maimed sparrows, fur balls and shredded soft furnishings.

With a sigh of relief I return the creature to its rightful place on the dark, dark shelf and reach for the next box, the one with the inverted pentagram, several occult symbols and sinister scratching noises emanating from within.

Steve Eddison is a key stage 2 teacher at Arbourthorne Community Primary School in Sheffield.