Supermarkets are another world, their entrances portals into another dimension.

I've always thought so. Not literally, but mentally. Emotionally, even. The cool air envelopes you, welcoming you in with a sly grin. The shoppers know they are strangers in a strange land and avoid your gaze, concentrating only on keeping the trolley wheels straight or getting the longest 'Best Before' date, even if it means digging to the back of the shelf. The queues at the checkouts are the border control for exit, and only those who can pay their way are allowed to leave.

I wonder if there are lost shoppers, wandering the aisles, penniless and, so, confined to that alternate dimension. They watch as visitors pass through the checkouts, oblivious to the true nature of their location, and mourn for the life they once had when they were OUTSIDE.

Shopping is lost time in the worst way, more so than a bad film you've paid to see and refuse to leave because you've parted with your cash. We had tried online shopping. Having a van deliver it to our door at a time when it suited us, but Amanda had struggled to find the last item we'd needed so gave up, deleting the whole list and throwing away the 45 minutes it had taken us to get that far. She would rather go and see what she's buying. Check the freshness. Dig for the longest dates.

Sigh.

So, I went. I wandered and I filled my trolley, putting in a couple of things I didn't need just to spite the supermarket and my wife's lack of patience, knowing neither would care and Amanda would think it funny.

Clothing sections in such places can be hit and miss. I can scan around them, thinking no-one would buy the oddly designed or ill-fitting garments, but occasionally, something would catch my eye. A top. A nicely laced and well supporting bra. Pyjamas I could slob in in front of the television with my friend Jack to keep me company.

I was there. It was my choice, as I'd decided to treat Amanda. I may as well look.

The woman was short. Rolling-gait heavy. Hair that had been box-dyed so many times it had actually died. We should hold a service. A brief memorial amongst the knickers and jimjams. She pulled various items of clothes, almost randomly, from the rails and took them into a changing cubicle, pulling the curtain across. That wasn't an issue. That wasn't suspicious.

The price tag still hanging from the inside of the jacket she was wearing, coupled with the furtive way she was looking around – a nervous mouse in a maze, sniffing out the plus-sized cheese at the end – was. I imagined her having a half hour or so on the Facebook Marketplace or eBay within the next hour or two.

I took a blouse down. It was my size and, I thought, might suit me. The colour would go with my hair and not make my paler-than-I'd-like complexion appear washed out. I could hear the woman grunting and panting from within her cubicle. The top of the coat hanger was metal and, with effort, straightened as I approached the changing rooms. I tried my best to be aware of the CCTV camera locations without blatantly looking, and hid my damage to the coat hanger beneath the blouse.

"Got em," I heard the woman whisper.

An indistinct voice, obviously from her phone, responded.

"Yeah, your size, don't worry. Tenner to you."

A pause, on both sides, then what must have been agreement.

"Right, come round mine later."

I walked in to the line of cubicles just as her curtain was pulled back and she exited. Her hands were empty, and she was looking much broader than she had when she went in. She was wearing jeans where before she'd had n only too tight leggings. I gripped the metal part of the hanger, allowing it to stick forward through my fingers.

It'd be a shame to get blood on the top. I quite liked it.

She wasn't wearing glasses. That was good. Easy access to her eye.

The woman stopped dead, appropriately, staring at me. She clearly forgot that other people could use the cubicles too. She looked back into the one she had vacated, then at me, then down at herself.

Would you like to be a little more obvious?

She opened her mouth, twice, to say something, but the layers of unpaid for clothes seemed to be suffocating her thoughts. She took a step forward.

"Awrite?" she nodded.

One step falteringly became two became three and she walked towards, then past, me. I watched her go, face impassive as, just before she disappeared towards the exit, she glanced back and gave me a middle finger salute.

Nice.

I turned back to the cubicles and chose a different one. The blouse fitted nicely. I bent the hanger roughly back into shape and went through the self-service lane to pay for it and the ingredients of my evening meal. I had to wait for one of the shop assistants to remove the security tag and wondered how the woman had managed to escape, considering she must have had multiple ones ready to set off the alarms the first chance they had.

I had my answer as I left the supermarket.

She hadn't. She was having a heated argument with a security guard, with what appeared to be the shop manager looking on, along with a small group of onlookers.

She stopped shouting when she saw me pass. I nodded and returned her salute.

"Awrite?" I laughed.

My smile was fake and forced. My laughter the same.

I drove home in silence, not bothering with the radio. The presenter would only get on my nerves, I'd flick through stations when adverts came on and the whole thing would just feel as if it was telling me what I already knew.

I was supposed to be waiting. Taking a break. Not taking chances.

If that was the case, what the Hell was I doing?

So what if the woman was stealing! What did it have to do with me? If I was so bothered, I should have reported her, not almost killed her! I wasn't some sort of vigilante, going after evil doers in a mask and cape.

Masks were for playtime with my wife.

I was supposed to be learning. Fulfilling. This was neither. This was opportunity and hunger. This was an impulse that threatened to become desire. It was foolish and needless and not even close to what I intended.

Was this how the famous serial killers had started? They just wanted to see what it was like, but got so caught up in the taste and the chase that they couldn't let it go? Though they might lie to themselves, thinking they're helping people or punishing 'baddies', it came down to the same thing.

And I was under no illusion.

We were killing. Ending lives that could flourish and blossom and do so much good. And that wasn't good. That was, in fact, rather bad. But I didn't feel bad. I didn't feel like a monster. I was just satisfying my... I can't call it curiosity. It was more than that. I was just a normal person. I didn't steal. I wasn't, usually, nasty to or about others. I just wanted to go about my daily grind until I could be at home with my family.

That's usual, isn't it? That's what people do, right?

The murders weren't done because I had an axe to grind (or impale). They were not because I was mentally unstable and needed to be locked up in a high security wing, strapped down and injected with a cocktail of all sorts.

I preferred a Mojito, thanks.