The hubbub of conversation grew. My strident voice grew more impotent. They were not listening and Katie had moved from shouting to openly passing photographs around the classroom.
I quickly snatched them from her hands. They were of a dog - her puppy. How rude, I thought. It was all I could do to avoid shredding them in front of her eyes. Instead, in a desperate, furious attempt to regain order, I held them high.
"Listen! Imagine Katie's puppy was..."
Some thoughts ran through my mind... Roadkill?
Hacked to death by a mysterious cloaked figure?
Baked in an oven with Mediterranean vegetables?
Then inspiration... "Was being experimented on so that your make-up was safe to use."
The class fell silent.
"They couldn't do that, could they sir?" said Katie, with a note of panic in her voice.
"Is it right," I said, emphasising each word with thrusts of the photo, "to test make-up or hairspray or medicines on animals?"
I held my breath.
We'd moved from potential anarchy to the whole class hanging on my every word.
"No sir, that isn't right."
"What if they were testing drugs that would stop cancer?" replied Jordan.
They were off. Debate raged.
My only role became that of puppy photo bearer. At last one of these endless tough lessons with this seemingly apathetic group had taken flight.
Katie's dog - God bless you
Worst: It is ironic that the lesson I would most like to forget involved amnesia.
Mystery Mary was a story you wrote by piecing together who Mary - a victim of memory loss - was from her belongings. It could be used for coursework and my Year 11 group desperately needed coursework. I was their fourth teacher in a year and they had produced nothing.
And that's exactly what they intended to produce this lesson, too. It was last thing on a Wednesday and I was wallpaper.
I had to act. I strode towards my desk and, with a lung-bursting scream of "listen", karate-chopped the desk surface.
A minute passed before the incredulous comment of: "Look at sir's hand". It had swollen to five times its normal size - and hurt like hell.
They laughed long and very loud.
It was the longest hour of my life. Order was beyond me.
Yet I kept trying and, as the bell sounded, I made one final attempt at control.
"No one is leaving this lesson until all the pencils have been collected."
I stood in front of the door. The mob obeyed my wishes. I counted each pencil into the box. "Eleven and 12" I patted the lid on the box shut and proudly announced, "At least something has been accomplished this lesson."
Then the bottom of the box opened and pencils tumbled out all over the floor.
The class roared.
I fell to my knees, clawing them back into the box while the students surged out of the door. Some even gave me gentle, consoling pats on the back.
"Never mind Sir"
Liam Murtagh is an assistant head at King Edward VI School, Morpeth
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