Ye Xuan did not open the door immediately.
Three taps. A pause. Then a young man’s voice spoke in Mandarin.
“It’s Wei. Mrs. Tang said you were awake. If you’ve decided not to talk to me, at least tell me you’re alive.”
Ye Xuan checked the phone. A contact named Wei Jun had called eleven times since Tuesday. The last message read: I shouldn’t have left you there. I’m sorry.
He put the safety chain across the door and opened it a few inches.
The visitor wore a university hoodie beneath a rain jacket. His glasses were fogged. In one hand he held a paper bag of noodles; in the other, a folder swollen with printouts.
“Are you sick?” Wei asked.
“Something like that.”
“Your face looks worse than it did at the pier.”
Ye Xuan stepped aside. Wei cleared a space on the desk and set down the food. His hands trembled when he took the plastic lid off.
“Did the detectives find you?”
“Yes.”
“Did they say anything about Mara?”
“They’re still looking for her.”
Wei stared at the noodles. “She told us to leave before ten. I thought she was just annoyed that we kept asking questions.”
“You were there too?”
“Until nine fifteen. You stayed to copy the older drawings. Remember?”
“I don’t,” Ye Xuan said.
Wei looked up sharply. The answer frightened him more than an accusation would have.
Ye Xuan explained that he had woken confused. He did not tell Wei about the truck in Hangzhou. He could barely believe that story himself.
“You kept saying you couldn’t afford to miss the lab placement,” Wei said. “Now you can’t remember the lab?”
“I remember things I’ve studied. Not the things I’ve done.”
“That’s not normal.”
“No.”
Wei had known the previous Ye Xuan for almost a year. He offered memories of late buses, shared lunches and a lecturer who never finished his examples. Every story fitted the evidence around the room. Not one felt like something Ye Xuan had lived.
“Why did Mara want the old drawings?” he asked.
“We thought the contractor had changed a drain. She thought they changed more than the drawings admitted.”
Wei opened the folder.
It contained two versions of the maintenance plan and a revision list supplied to the student team. Several pages carried preliminary stamps; none was an approved record of the completed work.
Ye Xuan read every page. At the last sheet, the entire plan became clear in an instant.
The diagram symbols, revision dates and assumptions arranged themselves in his mind as neatly as parts of a machine. He did not have to recite them. He understood how they fitted, and where they failed to fit.
“This service wall is shown in two positions,” he said.
Wei leaned closer.
“It’s one wall.”
“On the newer drawing, yes. But the pipe route follows the old alignment. Both sheets claim to describe the completed installation.”
Wei ran his finger across the ink. “Could it be a drafting error?”
“Certainly. Or one document might be outdated. But they can’t both describe the same physical space at the same time.”
“What does that mean for Mara?”
“Nothing by itself.” Ye Xuan showed him the photograph of the wet seam. “We need dimensions. And we need to know which drawing the crew used.”
Wei turned the pages again, slower now.
“Yesterday you needed me to explain the legend three times.”
“Yesterday I wasn’t feeling like myself.”
Wei did not smile.
The clinician examined Ye Xuan, asked about his confusion and insisted that sudden memory loss required further assessment. Wei listened to the instructions while Ye Xuan studied the bill. His inherited bank balance would not survive many more surprises.
Outside, people hurried past the pharmacy beneath an advertisement for an Awakened rescue service. On its screen a woman leapt between rooftops; on the pavement below, a courier argued with a broken bicycle lock.
“Everyone thinks powers fix everything,” Wei said. “Mara used to say she would rather have an accurate drawing.”
Ye Xuan looked at him.
“You said she told us to leave.”
“Yes.”
“Then why did I stay?”
Wei tightened his grip on the folder.
“Because she asked whether you’d seen the name in the revision history. You said you needed one more look.”
“Whose name?”
“I don’t know. I went home.”
That was not enough to reconstruct the night. It was enough to ask another question. If his other self had remained with Mara, why had the camera shown him near the entrance instead of inside?
At the subway entrance, Ye Xuan took out Detective Reed’s card. He would send her the photograph and the unsent draft with their original dates, making no claim about where Mara had gone.
Wei stopped walking.
“What’s wrong?” Ye Xuan asked.
“The shared project folder. Somebody just replaced the revision list.”
“Who?”
Wei turned the screen around. The change log named Ye Xuan’s university account.
The timestamp was four minutes earlier.
For those four minutes, Ye Xuan had been walking beside Wei with his phone in his hand. The log did not prove who had used the account. It proved only that the account had been used.
And the new file was smaller by exactly one page.