Down below, the factory whirred and thumped as the machines jolted back and forth, spitting their contents onto the conveyors. From the control room, the plant supervisor looked out over the vast floor and marvelled at how far things had come in the past few years. Not so long ago there would have been a hundred workers attending the stations, but these days human intervention just wasn’t necessary – most of the time. He was fortunate they still employed someone like him. No doubt in the future there would be a machine to do his job too.

The man’s stomach grumbled. Tonight already felt like one of those shifts that would never end. He stood up and walked to the small refrigerator, where he pulled out the ham-and-pickle sandwich he’d packed for his dinner. He carried it back to his work station and sat down, then picked at the edge of the cling film when an alarm began to bleat.

‘Not now,’ he sighed, hoping that one of the workers would sort it out. He could feel the beeping sound working its way inside his head, a dull ache rising. As the alarm continued, he huffed and stood up. He left his sandwich on the bench and hurried downstairs towards the offending machine, which of course was at the furthest corner of the building. He didn’t notice the shadowy figure dart into the control room, closing the door softly behind them.

It didn’t take long for the supervisor to recalibrate the injector. It was the second time it had happened this week, which was somewhat disconcerting, given the machines had recently been serviced and usually ran like clockwork. He glanced back towards the control room, which was suspended like an eagle’s nest at the end of the factory. It was strange – he didn’t remember closing the blinds. Or had he? Working the night shift on too little sleep wasn’t exactly ideal and he did seem to be more forgetful these days.

Once more, the shadowy figure went unnoticed as they slipped back out through the control-room door, shoving a piece of paper into their pocket. The deed was done. You couldn’t change the past, but the future? Well, that was something else altogether.