It was Phix who suggested the change, sat on the sofa, long blonde hair a torrent of curls and mouth set in the familiar thin line of impassivity. Phix was a thirty gen and as such was born without a physical or metaphysical heart and therefore encountered none of the emotional issues I did.

"It's a simple op. Callan from Q block had it and he's a new man. Remember how he used to cry in the park when he found a dead pigeon? Well the latest mech hearts don't have any negative settings so he couldn't even cry if he found his own mother dead in the park."

It was a shame we couldn't share the macabre humor of these words. Phix studied me without any joy in those glorious blue eyes when I smiled at the inscrutable cruelty of the thirtieth gen.

"You'll never be sad. You won't get hurt and you'll never have to write poetry again."

When we were younger Phix had looked at the words I wrote and I had seen a frown wanting to emerge on that blank young face. That was unthinkable for a thirtieth gen, but it had been the first time I saw that whisper of impossible emotion in those perfect blue eyes.

"Words are supposed to make sense."

The thirtieth gen was the first to have all aesthetic markers bred out. For them, words were instructive and educational. Poetry was akin to washing machine instructions written in a foreign language.

I loved Phix. The thirtieth gen was incapable of loving, but despite the lack of a heart and absence of the biological and psychological requirements for emotional attachment I saw something in those blue eyes that told me I was loved in return.

After all, I was a poet. I knew all about love and how it could live in the corner of an eye.

Phix took a swig of beer and surveyed me sunk into my chair smoking a cigarette and longing for the thrill of potential harm that nicotine used to have. I smoked as a hopeless memorial to the days when you could be self-destructive. They were long gone, of course. Bred out of the population generations ago, but still there in the words of all those poets and writers of the past and a ghost in the veins of the poets of the present.

"Are you going to do it?"

Mechanical correction was never mandated but it was pretty much the done thing these days for the early gens.

"It's a big step. I know you can't comprehend it, but I love writing poetry. I love being grumpy. I love not knowing how I'm going to feel when I wake up. I love the idea of crying over dead pigeons in the park."

"You can still keep the positive emotions in a regulated form and Callan told me he finds that as time goes on he needs them less and less. He hopes one day soon to switch his heart to purely biological function."

Phix was beautiful beyond the obvious physical sense. We had all been engineered to meet the pinnacle of an agreed level of attractiveness many gens ago. It was different from that standardized elegance. It was the stillness that inhabited those perfect bones. It was not a gen thing. Although all thirties were tranquil and without emotion you could see the chemistry at work, keeping them as placid as sedated lab rats. With Phix it was different. There was a calm that came from the depths of the ocean where life itself began back in the days of wildcard biological development.

"You might want to speak to Callan from Q block," Phix said. "He might still be able to understand your emotional reasoning."

It wasn't the first time Phix's cool logic had broken my heart, but it would be the last. That night I sat up into the small hours and smoked, weighing the words and wondering how life would be with a mechanical heart. I sent a text to Callan to meet in the park the next day and when the buzz of life in the city was almost still I fell asleep in the armchair with a cigarette harmlessly burning down between my fingers.

The park was busy, as always. The regulatory requirement for daily exposure to ultraviolet and the fact that it was only one of three unshielded public places left in the city ensured this.

Callan sat next to me on the park bench. He was the same gen as me, a few years older I thought but definitely the same gen. He was dressed in red, in the single garment style much favored by the later gens. His beard was gone. I wore my usual jeans and sweatshirt. I usually enjoyed being a garment anachronism, but today I found no joy in my minor rebellion.

"It's like living in cotton-wool."

That was Callan's response when I asked him how life with a mechanical heart was. I am sure he meant it as a positive but the horror crept across my skin at the very thought of a life of absolute protection from harm.

I couldn't think of another question to ask him and so I sat there in silence watching the pigeons come and go as he constantly fiddled with the settings of his mechanical heart.

"I'm going to switch over to pure bio next month," said Callan as we said goodbye.

I remained in the park watching the children mill about until their ultraviolet requirement was met. I thought about when I had been required to bring Phix here. Children had to be accompanied in public spaces by someone who had passed their adult competency exams.

Our first visit to the park together was only a few weeks after I had passed my AC1 and I had only done that by rebelling against every instinct in my heart and intellect. I was incompetent in the eyes of the adjudicators and I knew it. I was proud of it.

There were other things I was not so proud of on that particular day as Phix walked in a straight line from one end of the park to the other, eyes straight ahead, not a single element of the beauty of the world finding its mark upon the child.

Although all homicidal urges had long since been vanquished from the gen stream I found the echo of an urge to kill Phix that day as my heart was corrupted by the overwhelming sadness that engulfed me when I saw the perfectly straight line the child walked back and forth on that summer day under a cloudless blue sky. Now so many summers later as I walked back to our block I rediscovered that old sadness and I knew what I had to do.

The operation was simple. When I returned to the block afterwards I saw a new shine in the corner of Phix's blue eyes. Pride. Acceptance.

It took me several weeks to get the hang of the controls, but in the end, I found the levels that suited most occasions. The only time I became a little muddled was on my trips to the park for my ultraviolet requirement. The mechanics of my heart always seemed a little wayward as I sat on the bench. I looked around for Callan to ask his advice, but he never seemed to be there anymore. I wondered if they had changed his UV times.

Of course, once I had settled into the routine of things the questions started from Phix regarding when I would be switching to pure bio. Callan had done it successfully a month before.

"I'm not ready yet," I said and dialed my heart down a little.

"Callan finds it much easier now that he doesn't have to worry about dials and switches and all those positives clouding his reason," Phix said, curly blonde hair cut short for the summer.

I dialed my mechanical heart up to maximum and did not engage the bliss limiters. It lurched hard inside my chest as I ambled into the kitchen, aching for ecstasy.

I drove images of Phix through my brain and my mechanical heart hiccupped and whirred. The sadness battled against the science as I returned to the front room.

My heart required ascension. It needed to be delivered in Excelsis.

As Phix had no heart, the easiest method was a slice across the throat. Phix collapsed with a gurgle that almost sounded like a giggle. I allowed myself one moment of pure joy. I loved Phix more than anything, even the poetry that I could no longer write.

The joy and the homicidal instinct left me as soon as I dialed my heart down to zero, as did everything else.

Phix died as I sat on the blood-drenched sofa and smoked my cigarette. For some reason, I thought of the pigeons in the park.

I had no idea why.

Gary Priest

My Mechanical Heart