Câu thần chú chưa hoàn thành sau tan học

Prologue: The One Who Stayed

The dismissal bell cut the corridor in two.

The first half was running footsteps and the rasp of zippers yanked open. The second half held only a mop, a bucket, and a name circled in red on the duty roster.

Aoba Tōru looked at his own name and sighed. Still stuck wiping the blackboard in his third year—it sounded miserable. In truth, he had volunteered to take someone else’s shift. That person had cram school. He did not.

The air in the classroom cooled by degrees. Outside the window the cherry trees were past their season; only a few blossoms refused to finish falling. Tōru wiped the board clean, set the chairs up on the desks, and was about to close the window when he heard, from the empty classroom next door, a faint sound like a fingernail scraping chalk.

He ought to leave it. Duty did not include minding other people’s business.

But the sound was too regular, as if someone were writing, stroke by stroke, a problem that would never be finished.

Chapter One: The Magic Circle Missing a Corner

The door of the empty classroom was unlocked.

Shirasaki Rin knelt on the floor, tracing a ring of intricate lines in white chalk. The pattern gave off a faint glow in the evening light, yet its easternmost edge was missing a corner, like a mooncake someone had taken a bite from.

“You’re in the wrong classroom.” She did not look up.

“I’m on duty.” Tōru held the mop in front of himself and felt as if he were confronting the supernatural with cleaning equipment. “That… is glowing.”

“Unfinished things glow.” Rin turned the chalk once between her fingers. “When they’re finished, they go out. Like a life.”

Tōru did not know which line he was supposed to answer. He only saw that her fingertips were white with powder, and that the corners of her eyes were red. The pattern gave a low hum and jumped. From the missing corner a small patch of color like sunset leaked out, then dimmed again.

“Don’t look.” Rin bent her body over the circle. “Look too long, and you’ll want to fill it in.”

“What happens if it’s filled in?”

Rin was silent for a long time before she said, “Then after school will end.”

Chapter Two: Don’t Finish It

The next day, Tōru was kept after school again. This time it was not duty. He had added a line for himself on the roster.

When Rin saw him, she hid the chalk behind her back. “You’re here to fill in the corner?”

“I’m here to mop.” Tōru was honest. “I can’t fill in a corner. I only scored sixty-two in math.”

She stared at him for three seconds, then suddenly smiled. The smile was put away at once, as if she were afraid the pattern would record it.

“Don’t finish it.” Tōru set the bucket down. “If you don’t want after school to end.”

“That’s not how the spell works.”

“Then who decided how the spell works?”

Rin’s lips moved. She did not answer. Outside the window someone on the field shouted, “One more ball,” the voice so distant it seemed to belong to another season. Tōru started mopping, and on purpose dragged water over the missing corner until that patch could no longer be drawn on.

Rin looked at the puddle. For the first time, she was not angry.

“You,” she said, “are awful.”

“Duty students are all like that.”

Chapter Three: Seventh Period at Starlight

Starlight High’s timetable had no seventh period. But whenever Rin began to draw the circle, the clock on the wall ran an extra forty minutes.

In that surplus of time the corridor was empty. The vending machine dispensed only lukewarm barley tea. The announcement looped the same line: “All students, please leave the school grounds as soon as possible.”

“This is seventh period.” Rin handed Tōru the can of barley tea. “Today’s lesson: how to hold onto an afternoon you don’t want to end.”

“And the teacher?”

“The teacher is this missing corner.” She tapped the floor. “It’s been waiting for someone willing to fill it in. The one who fills it in may make a wish. The price of the wish is—this stretch of time will be withdrawn from everyone’s memory.”

Tōru held the can, which was no longer cool. “Including you?”

“Including me.”

He thought for a moment, took the chalk from her hand, and tucked it into his pencil case. “Then I won’t fill it in. Class is changed to self-study.”

Rin looked at her empty hand. The tips of her ears went red. “What do we write for self-study?”

“The duty roster.” Tōru said, “Tomorrow it’s me again.”

Chapter One: The Transfer Notice Is White

The transfer notice was white, whiter than chalk.

The homeroom teacher set the envelope on Rin’s desk and said the paperwork would be finished next Friday. Someone in class started the teasing—“Shirasaki’s going to the big city”—and Rin only pressed the envelope beneath the draft of the magic circle.

After school, the missing corner in the empty classroom was larger than yesterday. As if someone had torn a piece of the ending away in advance.

“You could wish to stay here,” Tōru said.

“A wish means filling in the corner.” Rin shook her head. “If I fill it in, I won’t remember you. I’d rather remember that the duty student is awful than have a clean after-school with no you in it.”

Tōru picked up the transfer notice and drew a very ugly mop on the back. “Then we change the spell. We don’t fill in the corner. We lose the notice instead.”

“That isn’t magic.”

“It’s duty.” He said, “Duty students are in charge of disposing of unwanted paper.”

Chapter Two: A Duty Roster for Two

The duty roster went from one person to two.

Rin’s writing was beautiful. Tōru’s looked like something crawling. Their names were crammed into the same square. The class officer drew a question mark beside them in pencil, and in the end never changed it.

Seventh period became ordinary. Rin taught him how to read the pattern. Tōru taught her how to scrape the chalk dust clean out of the blackboard tray. The barley tea went from warm to iced, because Tōru had learned to walk to the vending machine farther away.

“What if the transfer never goes through?” he asked.

“Then the spell will stay unfinished.” Rin pulled her hat low. “Unfinished is fine. Only complete things come to an end.”

The pattern brightened, faintly, as if in agreement.

Chapter Three: Unfinished Is the Spell

On Friday morning, the office said one letter of guarantee was missing from the transfer documents. The letter was in Tōru’s pencil case, lying with that stub of chalk, a ring pressed into it by the barley-tea can.

Rin stood behind the window and watched him. She did not go in to claim it.

“Unfinished is the spell.” In the empty classroom she wrote the sentence beside the missing corner. “Whoever finishes it is a traitor.”

Tōru leaned the mop against the door. “Then I apply to be an accomplice forever.”

Rin nodded, solemn as if some ceremony were being held. Outside the window someone shouted again, “One more ball.” This time, neither of them looked.

The clock still ran an extra forty minutes. No one filled in that corner.