The witness had driven past the compound twice and remembered neither face.
The first trip had been in daylight, with empty crates stacked behind his cab. The second was near the end of a shift. He had taken a document envelope from a dispatcher and delivered it to the service office. He could describe the envelope’s seal and the instruction written across the top. He could not identify the person who had prepared it.
Wanjiru explained the account without giving the driver’s name. The investigator had spoken to him through his employer, and he did not want his identity passed to the family while rumours about paid testimony continued.
“Is he the driver from the airport booking?” Yanchuan asked.
“No. This was a local courier working the service route.”
“Then there were two envelopes?”
“We know of one envelope connected to the transport invoice and one delivery described by this witness. We do not yet know whether they were the same item, copies, or unrelated.”
Yanchuan looked at the two invoices. One listed a returned sealed envelope. The other had a service charge without a contents description. His mind filled the space between them with his brother’s missing acceptance package.
He could already hear Mei asking whether he had matched the document numbers.
He had not.
The driver remembered being delayed at a junction by roadworks. An searched the contractor’s travel reconciliation and found a charge for waiting time that could fit the account. The amount was small and had been approved alongside a batch of other transport expenses.
“That’s corroboration,” Yanchuan said.
“Of a delay, perhaps. It still doesn’t tell us who gave him the envelope.”
“Do you ever get tired of making a useful detail smaller?” Yanchuan asked.
“Every day,” An replied. “I’m trying to keep it useful.”
He heard a receipt printer start at her end of the call. She said she would send the reference when she was free, not before.
They asked the investigator to compare the driver’s description with the underlying dispatch order. The request could be made without telling Yanchuan the man’s name or asking him to contact the driver.
For several days Yanchuan found this infuriating. He had a witness who could describe a delivery, but not a face; an invoice with a route, but not a named passenger; a register bearing his brother’s name, but no confirmed exit.
He began drafting a chart with boxes for each absence. Then he stopped. An had once told him that putting unrelated silences next to one another did not make them speak.
At work Guo’s preliminary project produced a similar temptation. The firm’s proposed model assigned failure probabilities to service contracts. A supplier’s historical data set contained fields for resolved, disputed, and no claim received. The last category had been treated as successful performance.
Yanchuan asked why.
The analyst said that a customer who had not claimed a penalty probably had no grounds to do so.
“Or the customer couldn’t document the failure,” Yanchuan said. “Or the claim cost more than the compensation. Or the service was never called.”
The analyst paused the presentation.
Guo asked how they would measure those possibilities. Yanchuan did not know. He suggested displaying them as unknown outcomes rather than silently placing them among successes.
The expected return fell when the model was recalculated. Guo studied the new figure, then asked for a range instead of a single answer. He did not seem surprised that uncertainty could be expensive.
When Yanchuan returned to the family file, the driver’s account looked different. Not stronger, not weaker: more accurately bounded. The man had described work he remembered doing. He was not obliged to remember what nobody had asked him to observe.
Wanjiru’s next message confirmed that a dispatch instruction existed for the service run. It recorded a sealed packet consigned to document control. The original recipient field was an office code, not a person’s name. The courier’s account was broadly consistent with that instruction. It did not identify the contents.
“Can we ask whether the packet is still there?” An said.
“Yes,” Wanjiru replied. “And who received it. Through the organization holding the record.”
Yanchuan wrote the questions down. He did not add an arrow to the airport journey until someone could demonstrate a connection.
That evening Jianming sent a photograph of the repaired lamp. It sat on the windowsill in Wuhan, its cord routed neatly along the wall. Beneath the photograph he had written, The new switch works, but the bulb still flickers.
Yanchuan called him.
“Did you replace the bulb?”
“Not yet.”
“Then you don’t know which part is wrong.”
“That’s why I sent you the photograph,” his father said. “I thought you’d enjoy being told you don’t know something.”
He laughed. For a minute the case stayed closed on his laptop.
Before bed, An forwarded a message from the investigator. The courier had agreed to preserve his original route notes and to answer further questions through the case team. He had not agreed to be named publicly, and the family would respect that.
Yanchuan saved the summary without trying to uncover the man’s identity.
The witness could not put a face in a vehicle. He could put a packet in the movement of a particular working day. The passenger field was empty in the original route note. It remained empty in the copy Yanchuan filed.