It's Thursday and I'm standing in the desolate concrete piazza looking up at six storeys of brutalist forgetting. One storey for each of your days of the week. I'm thinking of the systems, the laptops and the phones that don't store your name. I'm recollecting blank expressions that don't stay blank for long—only because everyone is so busy. Especially today. Always today. For today, they're one woman short.

How long had it been going on before I noticed the phenomenon? Hard to say. The weeks are rhythmless now. Work from home, come in on different days. It all depends. Then there's the hot-desks, the new office layout with its quiet rooms and mindfulness spaces and strange, curtained-off, meeting enclaves. No one is reliably visible in this “future-facing” place.

I remember saying, “I'll liaise with Lorna on this,” and Mike staring at me uncomprehendingly. Something similar may have happened before, but this is the earliest memory of which I can be certain. I walked away, somewhat nonplussed. But Mike's wife had been ill and was only recently out of hospital. Odd things are often easily explained. Mike, I supposed, was suffering from stress.

Then, a Thursday or two later, it happened again. I mentioned your name, this time in a meeting on Teams, only to be met by an array of perplexed faces. It was Holly who broke the silence. “Who?” was all she said. Of course, I've been under some strain too, as everyone knows, and so the moment passed without further remark.

It took several more incidents, several more embarrassments, for me to become certain of the pattern. On Thursdays, but only then, you were non-existent at work. No one knew the name Lorna Claxton. You were not an employee. You were not a colleague, let alone a friend. An email sent to your address would prove undeliverable— “Delivery has failed to these recipients or groups”—all emails sent by you were missing from my inbox, and presumably the inboxes of everybody else.

One can know a thing, be wholly convinced of it, and still be unable to make sense of it. I performed all kinds of awkward mental manoeuvres as I grasped for an explanation of your Thursday nonexistence; an explanation I already realised could never be there. At intervals, I even laughed about the situation to myself, though I felt no amusement. It took time for the weight of this impossible fact to press down fully upon me. Once it did so, that weight turned out to be hard to bear.

You are middle-aged, tall, and authoritative. These days, you're single. You have no children. You're good at your job. At work, your role keeps you slightly apart from the mainstream management structure. I've heard one or two people question whether your post is necessary at all—but only when the cycle of efficiencies starts up again. No one would question your worth to your face.

We're not friends. I admit, I once found you intimidating, but now I find you to be…well, something else.

We work in a building that looks like the headquarters of a post-war organisation of secret police. Such people are intent on knowing and remembering everything: endless names in endless files. But ours is a building of forgetting, the place where, once a week, you disappear. Of course, no one would know this if there wasn't a glitch. Your disappearance would be perfect. For reasons I cannot comprehend, I've been appointed the archivist of your absences.

I've given up trying to catch it out—the reality shift on Thursdays. Your erasure is smooth and subtle. Certain documents are edited, others disappear. It happens at precisely 1.32 a.m. and you return at the same time on Friday morning. I lie in my bedroom, my laptop open and watch it happen. Or, rather, I'm able to note that one second you're there, and the next you're gone. The process is instantaneous and cannot be observed.

And then, after it's occurred, I think of all the sleepers lying in beds a few miles apart who've had you taken, temporarily, from their minds. Every week a brief unpersoning. Is it done digitally, or is it a metaphysical event? I'm unable to answer. Does it happen to anyone else? I believe I'll never know.

The implications are enormous. Too big for a solitary mind to take. I cope by remaining focused on the individual human being who comes and goes. I have this intense, one-sided connection with you and it leaves me wakeful in my bedroom, talking to myself. I keep typewritten records, feeling furtive and obsessed. At work, I've cultivated an impassive face and my relationships with other colleagues have cooled. There are times when I feel it's me who is being erased.

With you…I can't pretend we've ever clicked. Of all the people to be chosen to remember you on your day of disappearance, I'll never fathom why it had to be me. My mind, I think, would have accepted your Thursday vanishing quite tranquilly. I talk to you more now than I ever did before, even as I talk less to others, but I worry my intentions will be misconstrued. And yet, it is as if I'm consumed romantically by you. You changed your hair from long to a bob and I dwelt on it for days. I notice new coats, new tops, I try to photograph, mentally, your face's every expression and to memorise the way you speak, the words you use and your inflections. I guess I'm searching for clues. I always imagined obsession would be strangely comforting, a kind of dreamy refuge from the world. But my fascination with you, Lorna, has left me feeling exposed. I'm hideously self-aware and always on edge at work. The possession of this secret brings with it the dread of being discovered.

And so here I am, boldly taking that very risk. I'm standing on your road. I'm looking at your house. No doubt this new phase is a dicey and unsavoury development. I'm aware I'm acting stalkerish, but I had to come. My investigation had reached its limits. My casual questions about your inexistent days haven't yielded results. I'm just not skilful or subtle enough. There was nothing else to try but to walk out into the night.

The wide suburban close is silent and empty. Most of the houses are dark now. Plush cars are parked in double driveways. You're certainly better off than I am. Your house is a good-sized detached. The trusting front garden, broad and tidy, doesn't have a defensive hedge, a wall, or a gate. I can see the cherry tree you've spoken about at work.

What happens inside at 1.32? Do you vanish from beneath the sheets? Vanish like your emails and our colleagues' memories of you. I picture it as being so peaceful. Or do you lie asleep for twenty-four hours, dreaming of your missing Thursdays? Are you forgotten by everyone, or just by those of us with whom you work? What happens when you take your annual leave? Are you ever allowed time off from taking a break from the world?

It's quarter past one. There aren't any lights on in your home. It's clear you've gone to bed. Your place is blank, an inscrutable face. I expect I'll learn nothing by remaining here. How many times do I have to remind myself that if this mystery is truly a mystery then it cannot be solved?

Especially from the unrevealing perspective of the street. I confess, I'd love to be closer when the moment comes. But this time that can't be done.

Again, I check my watch. Of course I'm going to wait.

A cat is trotting into view. He crosses the road, passing close by my feet. The high conifers stir in the breeze. Thin clouds drift past the moon which tonight is high and full and bright. I know I'm intruding, but the atmosphere on this sedate street is deep and easy to enjoy. You're about to be lost. With my mind that retains while others forget, I'm here to remember you.

The time is approaching. And so is something else. A glimpse of curious motion and I turn my head. I see it, advancing slowly along the curving pavement, moving with such care. For a moment, it looks like a giant, lanky insect. I have the impression of a large body and many legs. I feel the urge to run. I dart onto a driveway and crouch behind a car. I've lost sight of the thing that's on its way. I wait, quieting my breath. The cat reappears and rubs around my legs.

It—they—are coming into view, turning on to your drive. They're dressed entirely in black. Their hairless heads are bare. Their gloves, too, are black. There are six of them, bearing upon their shoulders a great dark casket. Silently, with solemn tread, they move towards your door. At your front step they pause. There's a moment of delay. The coffin shifts, a slight ripple passes through the group. One of those at the head of this appalling company of bearers has unlocked your door. Gravely, they walk in, taking the coffin over your threshold. No lights go on. From behind the car, I can just hear them step into the dimness of your home. I catch the sound of the coffin bumping gently against a wall.

I'm unable to move. I've never been so cold. I'm blank and frantic all at once. The wait is not long. They know their job. I can hear them coming. They're bringing you out. Bearing your weight in the capacious casket with bodies unbent. With just a few knocks and corrections they manoeuvre their load outside. On the driveway, they delay a moment and make adjustments. The pair I can see clearly, those at the front, look exactly alike. Their meaty faces are impassive and white. But then the one on the left lifts his head to look at the moon. And I'm struck by the resemblance between them—pale globes with faces strange to see and hard to read. But once again I'm wrong. The same one lowers and rotates his head. He's looking directly at my hiding place. He seems to know I'm cowering here. His expression now is impossible to mistake. He's smiling. Smiling. His smile is wide. His teeth are grey. He's smiling still. He looks utterly delighted.

***

Alex Older’s debut novel is The Animals Praise the Antichrist. His first chapbook, The Power That Overshadows, was published by Zagava; his second, Only Animals Can Make Me Smile, is forthcoming from Nightjar Press. He lives in the North of England.