Our friends had half-an-hour to get from Victoria, where we had been to a brilliant charity concert, to Liverpool Street to catch the 11.30pm train.

The happy, chattering crowds spilled out on to the streets from the Apollo Victoria Theatre where we had spent three hours or so in the musical company of Dionne Warwick and friends who were performing for The Hunger Project on World Hunger Day.

It had been a great evening, but now, as the audience dispersed, the streets started to look bare. Even London gets a bit quiet and spooky on a Sunday night.

With a substantial chunk of the Underground closed for engineering works, our two friends didn’t fancy their chances of making it in time and so, as we had driven up and left the car at Newbury Park, we stayed together in case they needed a lift home.

The Underground is a wonderful thing, but you need to know the rules and procedures.

n Never make eye contact, it is regarded as an invasion of privacy. If, however, someone should happen to smile at you, it’s okay to smile back – they are probably from Suffolk, too.

n Hold on to your purse/wallet. Having once had my purse stolen on the Tube I am a fanatical handbag gripper.

n If you are up from East Anglia for the day you probably won’t have anything to read so look up and absorb the route map opposite that shows the stops. Check each one with the recorded voice telling you the name of the next station and then count how many more before yours. In this way the journey will pass excruciatingly slowly, but you don’t want to appear a country bumpkin. On a crowded train it is permissible to look instead at people’s shoes.

n Breathe through the mouth. There is an unwritten law that the person who does not wash his/her armpits will hold on to the overhead handrail.

n If there is one remaining vacant seat it will have a strange brown mark on it and be between a man who sits with his legs wide apart and a woman with 14 assorted bags piled on her lap.

n If you are offered the seat which is designated for those with disabilities or who find it difficult to stand, ignore your arthritic knee. Perform a perfect pirouette and say: “Thank you, I’m fine.” If it is offered a second time, accept graciously and sit like a ballerina; knees together, feet pointed and crossed.

At Victoria Underground station we started at a fair pace, but gave up halfway down the escalator. We sort of knew 30 minutes wasn’t going to be enough; not with engineering works.

After 27 minutes, having negotiated parts of the Victoria, Bakerloo and Piccadilly lines, and having walked for what felt like miles through subterranean tunnels like refugees from the chorus of Phantom of the Opera it was clearly too late. The Norwich train would be gone.

Destiny had thrown the four of us together. As my husband commented, it had certainly thrown me together.

On some of the Tube trains we had bagged a seat, on others we stood.

A man in a greasy multi-zipped anorak sat next to me and dozed, his head lolling dangerously near my shoulder.

I once sat next to Graham Norton on the Tube and . . . er . . . that’s the end of the anecdote.

When we arrived on the Central Line platform at Holborn, we piled on to the packed train. As we waited for it to leave the station, we were pressed ever more intimately together.

Eventually the doors closed and, almost immediately an intensely evil body smell wafted across the carriage.

It was as if the soft clunk of the automatic doors shutting had prompted its release.

Everyone played innocent. Every man, woman and indeterminate adopted a bewildered: “Blimey, where did that come from . . . it certainly wasn’t me,” expression before looking round accusingly, but without fixing the gaze.

Several people looked my way. I may be 55, but it wasn’t me. I admit that these days I do have a tendency to stockpile internal wind, but none of it had escaped on this occasion, honestly.

No, I dare say the accident happened while the perpetrator was minding the gap.

Our friend who, in order to protect the innocent we shall call Linda, was reminded of the time she got a tummy bug while on holiday in Egypt. After a day or two in which she was never more than 10 seconds from a bathroom, she believed herself to be much recovered and decided to go ahead with a pre-booked balloon flight over the Valley of the Kings. She was fine for the first few minutes of the 50-minute flight and then it got a bit grim and then grimmer, much grimmer.

As Linda, regaled us with the gory details, we suddenly found we had a lot more space in the carriage as our fellow travellers edged away. Her husband, unlike the rest of us and, I’m guessing, having heard the story before (got the T-shirt, washed it, etc), had been listening carefully to the tannoy announcements.

“This train is the last one to Epping,” he said, quietly. “Are we on the right train?”

We weren’t.

The rest of us had slightly misheard the conductor when she said: “This is the last Epping train.”

We disembarked at the next stop where someone at the end of the platform was resisting arrest (I don’t think there is an offence of breaking wind on public transport) and hopped aboard the last train to Newbury Park.

Simples.