Three days in, I started testing the boundaries.
Not out of boredom—I wasn't bored. How could I be bored when I could literally do anything? But there was something about living in a world that bent to my will that made me want to understand exactly how far that bending could go.
I started small.
"Mash," I said during lunch on day three, "what do you think about quantum physics?"
She looked up from her curry, eyes bright and attentive. "Quantum physics is fascinating, Master! The idea that particles can exist in multiple states simultaneously until observed has interesting parallels with Servant summoning. After all, the Throne of Heroes exists outside normal spacetime, and Servants are essentially quantum observations of heroic spirits collapsed into specific Saint Graphs—"
She continued for exactly two minutes and seventeen seconds, providing a coherent, informed explanation that would have impressed any physicist. Then she stopped, smiled, and said, "But I'm sure you already knew all that! Is there something specific you wanted to discuss?"
"No, that was... very informative."
The next day, I asked Cu Chulainn about his favorite color while he was practicing spear forms in the training grounds.
"Blue," he said without breaking rhythm. "Like the sky over Ulster. Like the ocean I crossed a thousand times. Like—" He went on for thirty-seven seconds before returning to his forms.
I asked Artoria about her thoughts on modern hamburgers versus traditional medieval cuisine. She gave me a passionate, perfectly articulated five-minute response about how culinary traditions evolve and both have merit, though she personally finds the convenience and flavor profiles of modern fast food to be surprisingly sophisticated.
They all had answers. Perfect answers. Answers that felt real in the moment but dissolved into that same dreamlike quality the moment the conversation ended.
But they only had answers when I asked.
I spent an entire afternoon just watching. Sitting in the corner of the simulator room, making myself... not invisible, but unnoticeable. It was easy. I just decided they wouldn't pay attention to me, and they didn't.
Without my prompting, they followed patterns.
Emiya would enter the kitchen at 0600, 1130, and 1730. He'd prepare meals with mechanical precision, occasionally making small talk with whoever wandered in, but always the same small talk. "Good morning." "The rice is almost ready." "Clean up after yourself."
Cu would train for exactly ninety minutes in the morning and again in the evening. Same movements, same patterns, like watching a video loop.
Mash would check on my room every four hours, whether I was there or not. When I wasn't, she'd adjust the bedding (which was already perfect), water the plant on the desk (which never wilted), and leave.
It should have been unsettling.
Maybe it was.
But there was something oddly peaceful about it too.
On day five, I decided to push harder.
I found Da Vinci in her workshop, surrounded by half-finished inventions and holographic displays. She looked up when I entered, that mysterious smile already in place.
"Ah, Master! Come to check on my latest masterpiece?"
"Actually," I said, "I wanted to try something. Is that okay?"
"Of course! I'm always happy to assist~"
I took a breath. "I want you to... leave Chaldea. Walk out the front door and keep going until you reach... I don't know. France. And then stay there for a week."
Da Vinci's smile didn't falter. "What an interesting request! But I'm afraid I have far too much work here to take a week's vacation. Perhaps you'd like to commission a remote-controlled puppet instead? I've been working on a design that could—"
"No, I mean really leave. I want you to go."
"I understand what you're asking, Master, but my current projects require my direct attention. The Shadow Border needs calibration, and—"
I concentrated. Go to France. Stay there for a week. Really go.
Da Vinci blinked.
Then she stood, stretched, and said, "You know what? A vacation sounds lovely! I'll head to France immediately. I've always wanted to see the Louvre again. I'll be back in a week!"
She walked toward the door.
I watched her go, feeling that strange god-like certainty that she would do exactly what I'd commanded. She'd walk out of Chaldea, journey to France, spend a week there, and return exactly when I expected her to.
Except...
"Wait."
She stopped instantly, turning back with that same smile.
"Come back."
Da Vinci walked back to her workbench and sat down. "Did you need something else, Master?"
"Do you remember what I just asked you to do?"
"Hmm? You wanted to commission a remote-controlled puppet, right?"
I sat down heavily on a nearby stool.
So that was how it worked.
I could change anything, command anything, make them do or say or be anything I wanted. But the moment I stopped focusing on it, they'd snap back to their default patterns. Like NPCs resetting when the player leaves the area.
"Never mind," I said quietly. "Thank you, Da Vinci."
"Anytime, Master! That's what I'm here for~"
I left the workshop and wandered through Chaldea's corridors. The sterile white walls, the humming lights, the occasional Servant passing by with a nod and a greeting. All of it perfect. All of it responsive to my presence. All of it fundamentally... hollow.
I found myself in the library.
It was vast, far larger than it should have been given Chaldea's layout. But that didn't matter here. Space was whatever I needed it to be. Shelves stretched up into shadows, filled with books on every subject imaginable.
I pulled one down at random. The Complete Works of Shakespeare.
The pages were blank.
I focused, and words appeared. Perfect reproductions of every play, every sonnet. I could read them. Understand them. Appreciate them.
But they were only there because I'd thought them there.
I put the book back and kept walking until I found a comfortable reading nook near a window. Outside, I could finally see something clearly—a garden. Not Chaldea's actual grounds, but an idealized version. Flowers that bloomed in impossible colors, trees that swayed in a breeze I couldn't feel.
"It's beautiful, isn't it?"
I turned.
Medusa stood a few feet away, her book tucked under one arm. She didn't usually speak first. That was new.
"Yes," I said. "It is."
She moved closer, looking out the window with me. "Athena's garden in the Shapeless Isle had flowers like these. They only bloomed at night, and their fragrance could make mortal men forget their sorrows."
"That sounds peaceful."
"It was lonely," she said softly. Then she smiled—a small, sad expression that felt more real than anything I'd seen yet. "But even loneliness can be peaceful, in its own way."
We stood there together, watching the impossible garden sway in the non-existent breeze.
And for just a moment, I forgot she was an NPC.
For just a moment, it felt like I wasn't alone.