With a sense of elation, I did my morning round of the shelves and rearranged the sitting cubes. Satisfied with my work, I let my gaze travel over the room. The library was ready for today's visitors, and so was I.

As usual, the hours before noon turned out to be the quieter part of the day. To make the best of this time, I followed Marjorie's instructions and unpacked a box with new arrivals, fitted them with a label, and added the titles to the catalogue. A few piqued my interest, and I was tempted to check them out for myself, but resisted. I already had three books at home. That was enough for the week. Once I had registered all the recent additions, I checked if I could find them in the catalogue on the public terminal and was delighted when my search worked. Next, I went through the rows with my trolley to sort out books in need of a new binding or restoration before the rising tide of customers kept me busy until lunch time.

By then, the rain had stopped, and while the streets were still wet, I went for a walk instead of visiting my new favourite restaurant. Even with their prices on the reasonable side, I couldn't afford to eat out every day. So I had brought a box with leftovers from dinner I planned to eat on a park bench somewhere. My hands buried in my pockets, I strolled through the allies towards the city park next to the university. It offered a great view over the old town, and I had fond memories of the summer when I spent countless hours learning my exams up there.

February wasn't the perfect time of the year to eat outdoors, but despite the cold, a few students occupied the benches, discussing and laughing. I felt a pang of nostalgia when I settled on a free one nearby, listening in to their carefree conversation. Back in my student days, I had never appreciated how much freedom and spare time I had. Life as an adult was far more complicated, and I wished I could have another year with no other worries than which courses would fit best for my schedule and when I'd find a moment to sneak away with Oliver.

Oliver. Why couldn't I ban the man from my thoughts for good? I had a job now, was about to make new friends, and knew it was time to move on. Instead, I came up here at the first opportunity, where I risked running into him every minute—especially on a Thursday when he was bound to leave the institute any minute. Right, I better left before it happened. I slammed the lid onto my lunch box and stowed it in my backpack in a hurry. But it was too late.

Before I could zip my pack, he came walking straight towards me in the company of a brunette clad in a fashionable coat and shoes that weren't meant for this weather. Had he already replaced the blonde from two weeks ago? I lowered my head, staring at my hands while I listened to their approaching steps crunching in the gravel.

"Lynn, is that you?"

No way to ignore him now. "Oh, hey Oliver, nice to see you, too."

A deep vertical fold formed between his brows. "What are you doing here? Stalking me?"

Heat shot into my cheeks, a dangerous mixture of anger and embarrassment flooding my mind. "This is a public park. I can eat my lunch wherever I want."

"Sure, sure, but do you even know how creepy it is sitting right in front of the institute? Stop waylaying me, or I'll call the police next time."

This was so unfair. I jumped up, ready to defend my honour, but he just took hold of the young woman's arm and walked her away. "Ignore her, Chérie. She's just a frustrated ex-student."

The girl he called by the nickname I'd believed he'd reserved for me glanced at me over her shoulder. "Who was that?"

"No one, ignore her." The mixture of pity and disgust I could read flickering across her face brought me close to tears.

Why had I come here of all places this town offered? I should have known better than risking to meet the man again and renew my heartbreak.

No longer hungry and fighting my emotional turmoil, I headed straight back to the library, where I sat down at the front desk on the empty premises. Perhaps I should go to the coffee shop to wind down? I checked my phone for the time. Almost going on one o'clock, so I'd better stay here or I would be late for the afternoon shift. Why wasn't Marjorie around when I needed someone to cheer me up? By now, she probably was out of her surgery. I hoped she was fine.

"Of course she is. For a human, she is a tough lady."

Cat's sudden appearance on my desk made me almost topple over my chair. "Hey, can you stop doing that?"

"Doing what?" He sat in the same spot as in the morning and yawned, showing off his pointy teeth and an adorable pink tongue. "You must learn to be more precise with your statements, my dear Lynn."

"Materialising out of nowhere. I'm not used to it." Okay, considering Cat was a magical being, my argument sounded lame, but after my lunchtime adventure, I wasn't in a mood for word fights.

"I don't materialise." He blinked and curled into a fluffy blue ball. "You got this all wrong, Lynn. I've been around and watching you the whole morning and am not more or less solid in the moments you see me."

"Wait, I thought you—well, somehow change your state of aggregation? From invisible and untouchable spirit to blue-glowing semi-solid?"

His trademark grin spread over his furry face. "That's an interesting view, but we are not talking about the physical world here."

"That may well be, but I have no clue what we are talking about. You don't look like anything I imagined encountering in the afterworld." At least talking to Cat wasn't as humiliating and infuriating as talking to Oliver.

"I wouldn't know about the human afterlife." Somehow, he put on a contemplative face. "Alright, since you asked and because I like you, I'll try to explain."

I waited while he scratched his ear with a hind leg. "Try to imagine a whole different world existing next to your bland, everyday one."

"A parallel world?"

"That's a fitting word for it, yes. So, these two worlds coexist and overlap at certain points, but are mostly separate and fitted with a distinct set of physical and spiritual laws."

"Okay, like two planes of the multiverse. I guess it makes sense—even if it sounds weird. And where do the planes touch? Somehow, you can shift between them, so there must be a portal or a gate, right?"

"Now you get the concept—I knew you were a clever girl." He ran a paw over his whiskers, looking smug. "Still, I don't leave my world, or plane, if that's what you want to call it. There are zones of friction between your—let's call it physical and my spiritual world, pockets of probability, where the boundaries blur. This library is one of them, but there are others."

While I tried to stomach this, I rubbed my temples. "So, you can't appear in my apartment, for example?"

"Only if it lies in a friction zone, but I doubt that."

"And how can I find out if it does?"

Cat's gaze reminded me of a Zen master for a second. Then he destroyed the effect by licking his nose before he answered my question. "Do you dream vivid dreams?"

"Yes, I think I do." My heart sank.

"And can you can remember what you dreamed of in the morning? Or have you ever seen the protagonists of a book come to life and talk to you?"

"Like you?"

At his nod, a wave of relief washed through my veins. While I had dreams, they never included visitors of the blue-glowing kind, so I should be safe in my own four walls. Cat closed his eyes and remained silent for a moment. "However, I don't know all the potential zones, and it is a fact they shift over the centuries."

"Huh. Is this why Lewis Carroll gave such an adequate description of you in his Alice books? Did he pass through this library or another zone where the planes touch?"

"You're right, it was another place, one I no longer can reach. Carroll was an interesting case, though. I dare say the man was obsessed with finding the friction zones. You can believe I had a few enlightening discussions with him."

"I bet." I wondered who else had visited the author while he worked on the Alice books. "So you were the inspiration behind his stories?"

"You do me too much honour, my dear. Although I might have nudged him in a certain direction sometimes."

Their encounters must have been more than interesting. I shook my head. "But how does this relate to Luca? Marjorie told me only the protagonists of popular books will or can appear in the library."

"Hm, an interesting theory, and she could be right. I must discuss this further with her when she's back." He twitched his whiskers and grinned. "You must understand my world is populated by many creatures and people, but only a few are drawn to the friction zones, and even fewer appear in this place. Now, by coincidence or an obscure law I don't understand, it seems this applies to those in popular stories only."

"They might be drawn by the attention paid to them in our world."

"Exactly." Cat nodded his approval. "But how can you be sure they haven't visited your plane before they appeared in a book?"

"Oh." I leaned back in the office chair. "You suggest they visited our plane out of curiosity, sparked the imagination of an author here, and ended being written into a story—a story that became famous afterwards?"

He winked at me. "An interesting thought, isn't it?"

"Sure, but if these creatures wander into our world before the story exists, it seems too much of a coincidence they all got discovered and written about by a talented author. And how improbable is it that all these stories become famous? Or is your plane a mirage populated by all protagonists of all the books ever written, but only the few famous ones develop enough power to allow them the transit, propelled by the amount of reads their stories get?"

"Another intriguing theory, I must admit. But it implies that to exist in my world, you have to be part of a story in yours, the creation of a human mind." His narrowed eyes suggested he didn't like this theory much.

"I guess." My head spun. Either his world was the product of human imagination, which reduced its importance to a hangout for fictional characters. Or human creativity was strongly influenced by certain visitors from another plane of the multiverse—which made humans look like uncreative copycats, unable to come up with new ideas. "So, what's the truth? Do the creations of an author end up as inhabitants of your plane, or do you people appear to a random author who subsequently will write about you?"

"Why not both at the same time?" Cat's grin grew bolder, but his body was already fading as he muttered a last sentence. "It's the old dilemma of what came first, the chicken or the egg, right?"

I wanted to dig deeper, but in a last flash of his grin, Cat was gone.