The trouble with the universe, and, let’s face it, there’s always trouble with the universe, was that it insisted on being continuous. Time flowed. Space stretched. All very worrying. But, at the same time, things happened in an order, usually involving breakfast, minor catastrophes, taxation and, obviously, death at some point. And this, surprising as it might seem, made people feel safe.

But some, shockingly brainy types, knew the hidden truth. Deep down, under the carpet of reality, where the cosmic dust gathered and even the laws of physics didn’t like to poke around, things were… less tidy.

This was where Professor Eustace Greenfold, Head of Theoretical Metaphysics and Strong Tea at the Unseen University of Temporal Mechanics (not to be confused with the Unseen University of Temporal Magics, which was very different), found himself peering one damp Thursday morning.

He had built a Planckoscope. A Plankoscope, the first of its kind, turned out to be a delicate instrument involving a lot of spinning mirrors. It subsumed a sacrificed toaster, and had an alarming number of disclaimers printed and scribbled on numerous posters and signs. It was designed to peer into the Planck scale; that tiny, jittering foam of reality so small that, well… that’s as small as it gets without being a nothing. It’s so small that it’s a domain where time stopped being time and starts being something else. Something closer to a sneeze in the fourth dimension. Probably.

And in all of history, no one had ever looked that close before.

Mostly because they had better things to do.

And so, when Eustace flicked the switch, the universe gave a small and wonderfully polite cough. Nothing dramatic. Just a suggestion that something very, very tiny had just gone very, very wrong.

“Hmm,” he said, which was the sound of curiosity wrapped in worry. The Planckoscope was showing not a blur, not a void, but something very like a door.

Not a real door. There was no knob. But it had hinges, and it creaked open.

Out of it stepped a man. Or something that looked like a man. The figure shimmered with the oily glow. It was clearly a thing not entirely committed to staying in one spacetime. The figure wore a coat. Black. Long. Hopelessly out of fashion. And the man had the expression of someone who had just misplaced several dimensions and was trying to style it out.

“You’ve cracked it,” the man-thing said, in a voice like static thinking about becoming music. “Jolly good! Well done. You’ve poked a stick in the gears of time.”

Eustace, who was mostly comfortable in committee meetings rather than poking sticks at anything, adjusted his glasses. “Are you from the future?” He asked, somewhat pointlessly.

“No,” the figure said, as if such an idea was clearly bonkers. “I’m from between. From the instants between instants. I live in the shimmer.”

“Oh right. I see…” said Eustace, clearly floundering, “So what… you’re… what, a quantum ghost type thing?”

“I prefer Chrono-Interpolative Agent. I live where the Planck time ticks. That’s very, very, very small increments. In parts of a second, that’s like, a decimal point with 45 noughts after it, followed by a 5. And then reality reboots.”

Eustace felt his brain trying to file for early retirement. “So, time doesn’t flow?”

“Oh, time flows, right enough, Professor. It’s just that underneath it, it sort of… jitters. At the Planck scale, there are no guarantees. One tick, the speed of light is fine. The next, up is illegal and gravity’s taking a holiday. We live in the foam, where physics goes to get drunk.”

The figure leaned closer. “And someone, you in fact, just made a window into that madness. Do you have any idea what that means?”

Eustace nodded, not because he had the first idea what it meant but more because he thought it would aid the flow of conversation.

“It means,” the agent continued, “you’ve punctured the illusion. If enough people start seeing the tick… the jitter… the shimmer… causality won’t hold. There’ll be paradox leaks. Probabilistic tremors. One moment you’re tying your shoe, the next you've turned into your own grandmother.”

Eustace sat down very suddenly, or possibly just ceased to be vertical in a statistically meaningful way.

“I didn’t mean to,” he said. “I was just…trying stuff. I thought it might be interesting to see really small things”

“Well,” said the agent, “I’ll show you.”

He clicked his fingers, a sound that echoed like a collapsing waveform, not that anyone up until that point had the faintest clue what a collapsing waveform might sound like, and suddenly Eustace was standing between moments.

It was like being underwater, except the water was made of potentiality. Stars flickered. Space was pixelated. Time, instead of flowing, twitched. It was all quite interesting really.

Everywhere around him, things weren’t quite finished.

A cat was both entering and leaving a box.

A kettle was almost boiling but freezing.

A politician was simultaneously promising and denying a policy whilst being shot with a holly bush.

And above it all, vast wheels turned; the machinery of the universe, rendering frame after frame of what people liked to call “now.”

“This is the shimmer,” said the agent. “A Planck interval. You’re standing on the seam between what is and what might be. Every second of your life contains umpti-gazillions of these. And they’re all stitched together by probability and assumption. You believe time flows, so that’s what it does.”

Eustace whispered, “So what happens if we stop believing?”

The shimmer shivered.

The agent turned slowly. “That’s why I’m here.”

He reached into his coat and pulled out what looked like a glowing paperclip made of cheese. He handed it to Eustace.

“This is a Temporal Thread-Stapler. You’ll need it.”

“For what?”

“To rebind the shimmer. You’ve let it loose. Your Planckoscope forced open the gap. Now reality’s tearing at the seams. Little things at first. Ghost echoes. Déjà vu. People stepping into a room and forgetting why.”

He paused.

“Then bigger things. History fraying. You’ll know… Whole minutes repeating. Empires undone. Afternoon tea arriving too early.”

Eustace looked at the device. “And I fix it by…?”

“Stitching the jitter closed. One moment at a time. Reasserting sequence.”

“Won’t that take forever?”

“No,” said the agent. “It’ll take until about ten past two next Tuesday afternoon, if you’re quick.”

And so Eustace morphed from a brain box-metaphysics nerd to cosmic tailor. The first man to consciously step between the ticks of time and do something useful, armed with a pre-loved stapler, a packet of extra strong mints, and a thermos of tea.

Meanwhile, the gears of the universe ground on and the other temporal mechanics of the University waited in anticipation.

Which is a horrible feeling if it goes on too long.