THE STORY · EPISODE 16
Yuki’s letter was unsealed.
It was not a paper letter. A half-written draft sat in the same folder as the evacuation guidance for everyone. No one was supposed to have seen it yet.
“Putting it here makes it easier to find later.”
Yuki spoke without looking away from the terminal.
Light made of words flowed across the floor of the shared room: guidance maps, staff contacts, a personal draft. The black shadow sent them through the same door without distinguishing between them.
Anyone with the link.
Everyone who knew the link.
Mana looked at the screen and began to read the draft’s first line.
About the day Mana goes home—
She looked away there.
Yuki noticed and turned the screen toward her chest.
“I haven’t worked it out yet.”
“All right. I won’t look.”
It was easy to say. It did not mean she had no wish to know what Yuki had written. Her own name had made her want to know all the more.
People in the corridor could see part of the draft, too. Did stopping the shadow’s flow require reading every sentence?
Error stood beside Mana.
“Look at how far it’s open, not at the contents.”
It connected with what she had said when Mana closed her notebook yesterday.
Episode 16, Illustration 1 | Protecting a private letter by keeping a distance
The staff member responsible for the room checked the sharing scope.
Who had Yuki meant to send it to? Had permissions been widened for the whole folder when she meant to include only the guidance? Had a link without an expiry been forwarded elsewhere?
Miscure set the public-sharing setting beside individual users’ permissions.
“Two places to close.”
Changing the link alone might leave permissions granted directly to other users. The staff member checked the visible scope one part at a time.
Yuki tried to remember everyone she had sent it to.
“That person, too. For the guidance. And then…”
She shook her head halfway through.
“I don’t remember everyone.”
Sapo wrote down as far as she remembered, leaving the unknown onward destinations unconnected. Logrin and the staff investigated the remaining history.
A Defense question appeared in the encyclopedia.
OPTIONAL QUESTION · 16-D1Give only the access that is neededWhat is the principle of least privilege?Open illustration & choices
Interactive answer checks and saved progress load with JavaScript. You can continue reading without answering.
“B. Give the people who need it only the scope they need. Letting everyone see everything isn’t always kindness.”
The shield brought part of the flowing words back inside the room. It had not erased them. It marked a boundary to stop them spreading where there was no reason to send them now.
Mana asked Yuki,
“The guidance is still needed, isn’t it?”
“Yes. I want to give it to the people who helped.”
“Then let’s keep a way to send the guidance. It doesn’t have to sit beside the draft.”
Yuki lifted her face a little.
Knowing she did not have to stop everything helped more than comfort just then.
The staff member disabled the public link.
Next, they reviewed unnecessary direct permissions. They prepared another route, within the checked scope, for people who needed the guidance. Meanwhile, the shadow kept searching for other doors.
Mana saw the draft disappear from the terminal’s list and felt relieved.
“They can’t see it anymore.”
Then she looked at Yuki’s face and realized she had gone too far ahead.
No longer visible did not mean never seen. If a copy had already been saved, restoring permissions would not make that copy disappear.
“We’re closing the routes that let it go out from now on.”
Mana corrected herself.
“The staff are investigating how much they can establish about anything already shared.”
Yuki nodded. Her fingertips still gripped the edge of her sleeve.
The doctor checked with the staff what should be reported: which information might have reached whom, what was known, what was not yet known. They did not paste the whole draft widely into a new place for the report.
Mana did not copy the letter’s words into her own notebook, either.
Protecting a secret did not require making another copy of it. She learned that from the distance Error kept.
The black shadow lifted the guidance map.
As if to say, Everyone needed this, didn’t they? Convenient sharing did not have to use the same door for everything. Mana considered the different recipients needed for each sheet being swept along.
“Restrict access to authorized users.”
Yuki softly repeated the doctor’s words.
“Limit access to the people who are authorized.”
An Attack choice lit up in Mana’s encyclopedia.
OPTIONAL QUESTION · 16-A1A public link exposes a private draftA broadly accessible public link exposes a private draft. What is an appropriate response?Open illustration & choices
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“C. Stop the public link and check the other permissions. Restore the necessary recipients and scope, investigate the effects, and tell the people involved.”
“Miscure, show the scope the staff have decided. Linklar, mark the routes where sharing is allowed. Securidon, don’t let it flow beyond them!”
At Mana’s request, chains divided the two paths. The guidance light reached the people who needed it. The draft returned to the storage place its owner had chosen.
The shadow tried to pull everything back into one stream. But the labels they had checked for who needed what did not become the same color.
The last black thread fell into a hollow in the floor. Mana brought the Securies close above it.
A blue droplet-shaped companion appeared. He held a sheet marked CONFIDENTIAL in both hands. Small drops of water remained beside him.
“Can what spilled be put back?”
He asked.
Mana shook her head.
“Some things can, and some can’t. That’s why I want us to check together where we send things from now on.”
The droplet companion gently straightened his paper.
“Leaky. Next time, I’ll ask where to put it.”
COL-012 — Leaky. The sixteenth companion’s name was recorded in the WS Encyclopedia.
Neither Yuki nor Mana tried to take his paper away.
Episode 16, Illustration 2 | Checking the next place without taking the paper
On the way home, Yuki stopped once.
“How far did you see?”
Mana did not hide the one visible line by saying, Nothing.
“As far as ‘about the day I go home.’ I didn’t read past that.”
“I see.”
Yuki moved a small stone with the tip of her shoe.
Mana did not ask what came next. She was close to making the other girl’s silence into proof that she was disliked. That was another thing she had not checked.
“I still want to go home.”
That much she could offer herself.
“But you can decide whether I read the letter.”
Yuki was quiet for a while, then smiled a little.
“Then I’ll give it to you when I’ve worked it out.”
It was not a promise for tonight. Mana did not hurry it.
When they returned to the doctor’s house, Logrin and Sapo were comparing the history of sharing changes.
The records for one period suddenly became much shorter partway through.
It was not only about what happened after public sharing was stopped. Earlier traces had become invisible.
Without touching Yuki’s letter, Mana opened a notebook for the investigation.
END OF EPISODE 16