When I got off the train I walked the short distance along the main station concourse, away from the ticket barrier, until I arrived at Cut Price Keys. I’d spotted the kiosk on the day I banged into Rebecca and her mother.

‘One copy please,’ I said and thrust the rusty key across the counter.

‘One moment, sir.’ The stooped proprietor, in his thick safety goggles, bent over his machine and sparks flew out from all directions. He didn’t look up. My own glasses were so thick that it was hard to see through the lenses but I’d decided to keep them on until the purchase had been made and I was heading home.

‘You can get a second one half price, sir.’ As he spoke, the old man carried on shaving detail off a metal strip. I wasn’t tempted by his sales pitch.

‘No thank you. One is enough.’

A young woman, Bella, as I surmised her name might be, stood behind me and shuffled from one high heel to the other. She looked like a PA, perhaps in the employ of a high-flyer like myself. I smiled at her, switching my copy of the Financial Times from under one arm to the other. ‘I hope you’re not in a hurry,’ I whispered to her.

The sparks had stopped flying and the elderly man, goggles removed, stared accusingly at me. He handed over the key and smiled in a conciliatory manner. I needed to regain my personable and nondescript persona.

I slipped the newly cut key into my pocket, which I patted down with the palm of my right hand, and Bella smiled. Another time I’d have been tempted to follow her, strike up a pleasant conversation and invite her to join me for coffee.

But today there was work to be done. I had to make final preparations for my master plan. The time was nigh. With a slight reluctance, I headed back.

Wednesday was the chosen day. Midweek was less likely to afford random surprises and although I’d tried to anticipate all eventualities, I knew I might need resilience and the ability to adapt at short notice. However, I wasn’t concerned. Imbued with an overwhelming sense of invincibility, I harboured no doubts as to the outcome of my plan.

I spent all day moving furniture into the middle of the rooms in my flat, preparing it for a makeover. Sometime after lunch there was a sudden persistent rapping on my front door.

‘Hello. Arthur? Are you there?’ I quickly turned down the music volume and yelled back.

‘Mrs Kennedy. Sorry, I’ve turned it down.’

‘Can you let me in? I need to speak to you. It’s urgent,’ she persisted. I peered through the eyeglass on the front door and saw her peer back. She was waving one arm frantically in the air, rightly assuming I could see her.