A slight pause in her breathing was the only clue Katie had given that she'd woken up. Someone was in her room; someone deliberately trying to be silent. There were no footfalls, rustling of clothing or sounds of breathing, but the floor had creaked. Having slept in this room since starting university, Katie was intimately familiar with the noises of every floorboard, and someone had trod near her dresser. Trying to shove down her fear, to not give any clue that she was aware, she concentrated on listening.

It was still dark outside. The sounds of birds were completely absent, so dawn was still some time away. It couldn't be anyone legitimate; her bedroom door had been locked, and the others she shared her dorm with weren't the sort to break in for no reason. If they did have a reason, they'd knock until she woke.

Was it a burglar? If so, she should feign sleep until they left. It wasn't as if she had anything valuable to steal, but if the robber thought they'd been seen, there was no telling what they'd do to ensure no witnesses. The last alternative was that it was someone here for her, but if that was so, why had they gone silent? Did they already know she was awake? Were they just standing there, watching her?

The minutes stretched on with no further sounds, leaving Katie wondering if she'd imagined everything. She opened her eyes a fraction, but in the pitch darkness, could see nothing. Doing her best to act casual, she stretched and grabbed the phone from her night-stand, climbing out of bed and using the phone screen to light the way to the door, acting as if she was going to the bathroom.

The phone screen failed to illuminate anyone. The room was empty. Katie threw the light-switch, checking the few places where someone could hide. Under the bed, in the cupboard, clinging to the ceiling. Nothing. Her door was still locked. The window was closed, locked and unbroken. She really had imagined it. She flopped down onto her bed, waiting for her heart to stop beating so crazily.

That was when she saw the new addition to her dresser. An unadorned silver ring, sitting atop a piece of paper.

Dear Katie
You don't remember, because I kinda messed up the timeline, but you saved the lives of a lot of people recently. Consider this invisibility ring your well-deserved reward. Go wild.
P.S. If you ever want to try out any of the situations described in those books you keep under your bed, just pray out loud to the Goddess. I'll hear you, and am always up for fun.
P.P.S. Watch out for traffic when wearing the ring! Road accidents are the number one cause of death for invisible people, and contrary to popular belief, trucks are not the route to an isekai adventure!

Katie immediately dropped to the floor and dragged out a large cardboard box from under her bed. It showed no signs of tampering and was still safely taped up. Yet someone knew about its contents. Someone who could sneak into her locked room, leave a 'present' and get out despite the only exits being locked.

Why would someone go to all that trouble to pull such an easily falsifiable prank? Was the ring trapped in some way? Would it electrocute her if she put it on?

The next five minutes were spent carefully inspecting the ring from every angle, poking it with a clothes hanger, flipping it over and checking the underside. It remained a perfectly smooth band of metal, with no visible surprise features.

In the end, failing to find anything suspicious, she gave the ring a few experimental prods with a finger. When even that failed to reveal anything, she slid it on.

Katie vanished.

Less than a minute later, the door handle clicked ineffectually, and someone knocked from outside. "Katie? Are you okay? I heard you scream!"

"I'm... I'm fine. Thanks Bell. I just had a... a nightmare."

"Do you want to talk about it? You sound awful."

"I... It's okay. Go back to bed. I'm sorry for waking you."

"Are you sure?"

"Yes. It's fading already."

Katie's friend and occupant of the room next door departed, leaving the shaking Katie sitting on her bed. The first thing she did was retrieve the clothes hanger again and wave it around her room. Obviously, just because no intruders were visible didn't mean there weren't any present. It took some time to satisfy herself that she was probably alone.

And if the bit about the ring was true... What about the rest of that note? How had she saved a bunch of people? It was hard to imagine how that could possibly have happened. She was just a university student!

And what was that about a Goddess? A perverted Goddess, apparently. One that had screwed up the timeline somehow. The note sounded like it was from the Goddess. If so, couldn't she have stuck around for a chat? Why just leave a note and run?

Was Daisy running some sort of experiment on her again? She'd grown progressively odder since starting her psychology degree, always analysing people. It was the sort of thing she might pull, but then how did the ring work? Perhaps she was starring on a hidden camera show, but again, the ring worked.

Katie slid it onto her finger once more, watching as her hand shimmered into invisibility, the effect leaping up her arm and spreading across her full body in less than a second, her nightie fading away to nothing a second later.

She stared into a mirror, seeing nothing but the wall behind her. Even leaning in close showed no sign she was there. That shouldn't have been possible. Katie may not have been studying physics, but she knew enough of the subject to know that eyes worked by absorbing light. If she really was completely invisible, to the point that she saw no sign of her eyes in the mirror, then she should be blind.

What options were there? If this ring didn't obey her understanding of physics, then the first option would be that her understanding of physics was wrong. She discounted that one immediately. If invisibility rings were a thing that existed, no-one would ever leave one with her. They would be carefully controlled by governments and spy agencies.

Option two would be magic. Something that acted outside the regular laws of the universe. She didn't like that one, either. It was, to put it simply, giving up. The theory was unfalsifiable. It would be like blaming God. Or Goddess, in this case.

That left option three; she wasn't seeing what she thought she was seeing. She could see how her mirror could be replaced with a screen, projecting an edited camera image to hide herself from it. But she didn't need the mirror. She only needed to look down to see the foot-shaped impressions in the carpet where she was standing, with a distinct lack of foot in each of them.

A screen over her eyes then? She waved her hand over them, but felt nothing. Contacts? Again, contact lenses capable of displaying a realistic image with no wires or power source wasn't technology that existed. She could be stuck in a deep-dive VR simulation, but as well as invoking technology that didn't exist, that was basically going back to option two again.

"Magic it is then, I guess," she muttered to herself, falling backwards onto her bed, still invisible.

If the ring was real, what were the implications? Did it necessarily follow that the note was real? Had Katie really saved lives? Was a Goddess really prepared to drop in for a booty call? Well, the note did say 'always', which again made it easily falsifiable. Katie merely needed to pray.

Despite the lack of observers, she blushed lightly, thinking of some of the things she kept under her bed. A lot of the contents were even less physically possible than the invisibility ring. Magic would certainly be required.

"Umm, Goddess, if you're listening," she started before stopping, her blush intensifying. If it was really a Goddess, why did Katie need to pray out loud? If it was, somehow, Daisy—if there really were hidden cameras somewhere, recording this—Katie's social life would be over. She'd have to flee, preferably to a different continent. Change her name and get a full course of cosmetic surgery.

Okay, maybe things wouldn't be quite that bad, but her dorm-mates would certainly never let her live it down. It was a simple case of potential payoff against the potential costs, and the ring had swayed the balance towards there really being something supernatural going on here.

"If you're really listening," she resumed, in a barely audible whisper, "perhaps one of the ones involving tentacle clothing?"

At what was, by complete coincidence, the exact second in which the sleeping Katie of another timeline had been teleported to a human castle, this Katie was teleported to a different sort of castle, one occupying a tiny pocket dimension, floating loose in the Void.

"Looks like I win, even if she did take a bit longer than I expected," said someone behind Katie in Katie's own voice.

Katie didn't turn around to look, though, her attention captivated by the being in front of her. Katie's shape and height, but instead of skin, she was covered in iridescent scales, flashing all the colours of the rainbow as they caught the light in the room. A pair of wings were partially visible, folded behind her, covered in the same beautiful scales. Her eyes were a bright yellow, with slitted pupils. Her hair was a shining silver, worn straight, long enough to hang below her waist. But none of that was really what Katie was focused on.

Katie's attention was drawn by the mass of tails waving behind her. Nine of them, each one fluffy enough to drown in. They were matched by a pair of fox ears atop her head, all coloured in the same silver. A silver, scaly, winged, humanoid kitsune? A very fluffy kitsune.

"Only because you wouldn't let me look," complained the kitsune, who once again appeared to share Katie's voice. And, now that she looked beyond the scales and inhuman features, didn't they also share the same face?

"And in what universe is looking at the outcome an acceptable part of betting?"

"Well, Anya was telling me about a curious group of shellfish on an oceanic world a few dimensions away that..."

"No, you know what, forget I asked. Besides, you have a guest to entertain."

"Oh, right! Hello, past me!"

Katie decided to shelve any complaints about the inane conversation, or why everyone had the same voice, or even the whole thing about there being a Goddess and that the Goddess was apparently her, in favour of focusing on what was really important.

"Umm... I know I mentioned tentacles, but first... Please can I fluff your tails?"

And that was how the new Goddess learnt for sure that whatever changes there may have been, at her core, she was still very much Katie.