Apparently, her man, Rab, was by far the worst off. Cuts to lip and eyebrow had been passed off as the results of a “fall”, but the “dispute” had been witnessed by several parents in the queue at Janetta’s chip shop. Elspeth certainly could be seen as a contender for Lennox Lewis’s title.

So, who was Tina? How come St Patrick’s forward plan was strewn all over the ladies loo at the Three Lions? I decided to investigate. My enthusiasm for Columbo, Maigret and Poirot had provided a good grounding in the sleuth’s trade and I determined to find the lady.

Who had access to the plans? It had to be teachers or cleaners. I went over the runners and riders.

Apparently, Tina had been quite good, even allowing for the wonders of modern technology, when even the most mediocre vocalist can sound versatile. I arranged to sit in different places at the next few assemblies to ascertain the vocal talents of my girls. I thought of appearances, and Tina had to be reasonably like the person she was impersonating.

Jim the jannie came up trumps. I sat him down, and we had a conversation about the Christmas holidays. I knew Jim was a regular at the Three Lions, and must have some insider knowledge. Jim described Tina as a “belter” and, in his humble opinion, well worthy of his company.

That ruled out Sally. Sally had been a “belter”, but not of the kind Jim the jannie sought. The removal of the tawse had coincided with the decline in her ability to control classes. I also knew she was tone deaf, but I did admit to a fit of the giggles as I imagined her in mini skirt and wig.

I narrowed the list of suspects down to three, after the first week of strategic assemblies.

Jackie McWilliam’s mum! Of course. She had seen La Turner minus wig, and had seen her at very close range. I arranged a visit. The excuse was to review Jackie’s progress, but the reality was quite different. Mrs McWilliams was a piece of cake. She blurted it all out, especially after a second cup of my finest Colombian coffee, with appropriate “additives”.

She launched into a tirade against that ***** woman, calling her all the names under the sun, and then some even my ex-foundryworker grandfather wouldn’t have used. Tina was apparently a southpaw, and led with her right hand. She had long fingernails - and the cuts they left were ”***** sore”.

She was also wearing a perfume that Mrs McWilliams referred to as “Channel 5”, but I knew what she meant. The hunt was on.

Two weeks later, I had drawn a blank. I had listened to all of them singing a wide range from Morning Has Broken to One More Step Along The Road I Go.

I had deliberately imagined them in leather mini skirts and wigs, and indeed had cut up copies of last year’s staff photo to create Identikit Tinas. No luck.

Who was the culprit? I needed an assistant. Joan was a big Rebus fan, and she might be up for the challenge. I brought her up to speed with my research, and explained my frustration. Joan was good, and her analytical mind had not been too badly affected by the years of Chardonnay abuse.

Joan searched the internet for Tina Turner pictures and personal details of the superstar. We looked at all the possibilities, but Joan too was finding it difficult to identify the guilty party. We chatted for ages, and then I noticed the timetable on her wall for visiting specialists.

Of course! I had forgotten that I had visiting specialists in the first term. Joan and I shared specialists as part of our cluster arrangement. It had been my turn to have Dorothy, the music specialist.

Dorothy could sing. But was she right-handed? Was she the proud possessor of well-manicured fingernails? Was she wearing that perfume? Did she need a bob or two of an evening? Surely not?

Joan looked at the Tina fact file. Height was a possibility. Weight - maybe.

The net was closing in. I admit I was getting quite excited. The effect of Joan’s endless supply of coffees was beginning to tell. I excused myself, and asked Joan where her loo was.

I was sitting in cubicle two, minding my own business, when I heard a sound emanating from cubicle three.

“Still I love you, my oh my . . .

River deep, mountain high . . .”

I nearly had what my mother used to refer to as a “wee accident”.