Grin waved a hand.
"No need to be so formal. Just call me Grin. By the way, where's the toilet? Or the bathroom?"
Subaru raised a finger and pointed toward the room he had just been blasted out of.
"What a coincidence, Grin-kun. This is actually the toilet."
"No way. You little punk, are you messing with me?"
Grin stared at him in disbelief.
"That is absolutely not true, Mr. Grin!"
Even as he said it, though, a mischievous grin flickered across Subaru's face.
If a guest got blown away by that drill-haired little girl too, it would really be a terrible loss of face.
Grin swallowed hard and stepped toward the door, trying to comfort himself.
"As everyone knows, the chance of two shells landing in the exact same place is less than one percent."
Creak—
The door opened a crack, and soft light spilled out.
Inside was a vast room.
Towering bookshelves stretched all the way to the ceiling, packed with countless magic books that carried the scent of old paper and faint mana.
Beatrice sat curled up on a wooden bench in the Forbidden Library, her cream-colored twin drills falling over her shoulders, the hem of her ornate frilled dress swaying softly.
The girl, who looked no older than eleven or twelve, did not even lift her head.
Instead, she said coldly,
"What? Does Betty look like a cannonball to you, I wonder?"
Bang.
Grin slammed the door shut.
Then he slowly turned and stared at Subaru, who answered him with nothing but an awkward laugh.
Crack.
Grin flexed his fingers until the joints popped, then began walking toward Subaru step by step, looking very much like a man about to commit violence.
Subaru turned pale and backed away.
"I swear, I swear, this really is the toilet!"
Grin let out a long breath and forced himself to calm down.
"I'll trust you one more time. But if I get beaten up too, you know what I'm capable of."
"Okay, okay!"
Subaru had no idea what Grin's methods actually were, but he still nodded repeatedly.
Creak—
The wooden door opened again.
"As everyone knows, if the shell hits three times in a row—holy crap, forget it, let's go find a different bathroom!"
The moment Grin saw the room unchanged inside, he spun around and tried to flee.
"Ah—help—"
Before he could finish, a powerful suction force burst from inside the doorway and dragged him straight in.
By the time his footing returned, he found himself standing right in front of Beatrice.
Bang!
The wooden door closed on its own behind him.
"One fool after another. Roswaal certainly has a talent for attracting idiots to this mansion, I suppose."
Beatrice held an old book in her hands and looked down at Grin.
Grin stood up and brushed dust and wrinkles from his clothes.
"I wasn't trying to come in at all…"
That made Beatrice frown slightly, and her tone sharpened.
"You've been playing with the crossing door this whole time. Betty is practically catching a cold from it, in fact."
Grin paused, mildly surprised.
So the crossing door really had opened in the same place three times in a row?
That should have been impossible.
The access points to the Forbidden Library looked random on the surface, but in truth, they were controlled by Beatrice. If she did not want someone to enter, the only way to find her was to open every single door in the mansion.
"Beatrice… did you actually need to talk to me about something?"
It was the only explanation Grin could think of, so he tried it cautiously.
The proud Beatrice had her thoughts exposed on the spot, and a faint blush rose to her cheeks.
"He's slightly smarter than that reckless fool from before."
Still holding her book, Beatrice gracefully stepped down from the wooden stairs and stopped in front of Grin.
She stood at only around one-forty, and her delicate little leather shoes clicked softly on the floorboards.
Then she raised a hand and placed it against Grin's abdomen.
The move startled him so badly he immediately stepped back several paces.
"Beatrice, I'm injured. Can you wait a few days before draining my mana?"
"Idiot! Do not misunderstand Betty's actions, I suppose! Betty was only sensing another life inside you out of curiosity. Also, call Betty by her full name—Beatrice! Hearing you say 'Betty' makes Betty extremely uncomfortable, in fact!"
She stamped a foot, both little fists clenched tight.
"Okay, Betty. No problem, Betty."
The rebellious streak in Grin woke up at once.
Provoking proud, tsundere types until they exploded was one of his specialties.
"That damned man!"
Furious now, Beatrice reached out again, clearly intending to draw some mana from him this time.
Grin was ready for it and let her small hand settle against his lower abdomen.
Buzz—
The mana transfer began.
Beatrice drew out a stream of pure yin-attributed mana.
And yet strangely, Grin did not react at all.
"Ah! What is going on?!"
A shrill scream came from beneath Grin's shirt.
Then a golden mirror burst out and flew into the air.
"Who did that? Who did that?! Which blind idiot dared steal my mana?!"
The magic mirror hovered there, shrieking in outrage.
Grin slapped it on the head.
"Don't copy me."
"Ow! Yes, Master! Who's draining my mana? It's you, you little brat! I'll chew your soul to pieces and swallow it whole!"
The mirror immediately locked onto Beatrice.
Only she and Master were here, so naturally it had to be her.
Beatrice carefully studied the magic mirror, then reached out and caught it by the handle.
"It seems you are not a spirit after all. Betty was overthinking things, I suppose. Still, Betty has never seen a talking magical item before."
"Let go, you rude brat! Don't push me too far, or I'll grind your soul to bits!"
The magic mirror kept shouting threats, utterly unaware it had just stepped on a landmine.
Beatrice hated being treated like a child.
Sure enough, the look on her face darkened the moment she heard the words little brat.
"As expected of an idiot's artifact. Even your words are irritating in exactly the same way, I suppose. There are a few loose bookshelves around here, so Betty will use you to wedge them in place."
"What?!"
The magic mirror panicked.
After all the effort it had spent restoring its handsome face, there was no way it intended to get scratched up again.
So it twisted hard, slipped from Beatrice's grasp, and darted back toward Grin.
In the process, it accidentally knocked the book out of Beatrice's other hand.
The old book fell to the floor.
Its pages fluttered open wildly.
And strangely enough, the inside was completely blank.
No writing.
No signature.
Nothing but pure white paper.
The magic mirror flew back onto Grin's shoulder, suddenly much bolder again.
"So you've been pretending to read nonsense this whole time? What are you acting like some cultured person for?"
Then, lowering its voice, it whispered into Grin's ear,
"Master, hurry and give her a poisoned apple. Trick her into eating it. If we don't kill her today, things are going to get troublesome."
Grin's lips twitched.
He covered his face with one hand.
"As your master, I often feel ashamed."
Ignoring the mirror, Beatrice hurriedly crouched down and carefully picked up the book.
Still nothing.
Neither Subaru's arrival nor Grin's had changed a thing.
The book remained empty, just as it had four hundred years ago.
Grin knew about the verbal promise between Beatrice and the Witch of Greed, Echidna.
Beatrice had sworn to guard the Forbidden Library until "that person" appeared—the one fit to inherit Echidna's knowledge.
But Beatrice had placed too much of herself into the guidance of the Book of Wisdom, endlessly waiting for instructions that would never appear.
"Are you okay, Beatrice?"
Seeing the lonely outline of her small figure, Grin felt a tug in his chest.
If it had been him, he would have broken down long ago.
These spirits and spirit-like beings really did treat their vows with an almost obsessive seriousness.