Whenever Yan Qing encountered a body, her focus became absolute. Standing now before a forensic examiner whose experience and knowledge were both clearly limited, she had, quite naturally, begun treating him as one of her students.

Back in the forensic sciences department, she used to supervise students regularly. The interns would gather around with notebooks and pens while she performed her examinations, learning and recording as she worked. She had been the youngest female chief forensic examiner in the city, and the youngest instructor as well.

It was only when silence settled suddenly over the room that she became aware of what she had just said.

As she was working out how to walk it back, the haughty Dr. E — unwilling to be outdone — opened his mouth and answered with brisk confidence: “That’s a simple enough question. In a hanging, gravity causes the ligature groove to be deepest at the front of the neck. As it extends toward the left and right sides of the jaw, the impression grows progressively shallower until it disappears. Because the two ends do not meet, a blank area is left at the back of the neck — this is called the suspension gap, and it is a defining characteristic of death by hanging. In a person who has been strangled, on the other hand, the ligature groove runs horizontally around the neck in a closed ring at a uniform depth. Most critically, the groove forms a complete, unbroken loop with no suspension gap.”

The answer was entirely accurate. E Yuan had clearly committed the textbook material to memory with care. His deficiency lay in practical application, not in foundational knowledge.

“Then what do you make of this?” Yan Qing’s blade was deft and confident. Within moments she had sectioned through the skin at the neck.

All three leaned forward to look.

“Subdermal hemorrhaging!” E Yuan pushed his glasses up sharply.

The strip of skin Yan Qing had cut open showed hemorrhaging of nearly consistent severity throughout.

“The scarf is a soft material. When used to strangle the victim, it leaves almost no visible groove on the surface of the skin. However, under the mechanical force applied, the subcutaneous blood vessels rupture and bleed. The width of this hemorrhagic band corresponds exactly to the width of the scarf when twisted and pulled taut. It runs in a closed ring around the back of the neck. There is no suspension gap.”

Yan Qing lifted the victim’s two hands. “Additionally, the right index fingernail and the left middle fingernail are both broken — consistent with the crescent-shaped fingernail marks found on the victim’s own neck. After the killer seized her from behind, she struggled violently and tried to pull the scarf away, breaking her nails in the effort.”

Yan Qing raised her clear, bright eyes to Shi Ting. “The deceased was strangled from behind with a silk scarf, and the scene was subsequently staged as a hanging. This can now be classified as a homicide.”

On hearing this, E Yuan’s instinct was to challenge her — but he could find no grounds for objection. What he could not bring himself to accept was that a problem he had overlooked had been found by this young woman of means, and found with apparent ease.

“Additionally, based on the lividity pooling, the clarity of the pupils, and the onset of rigor in the lower jaw, the time of death was approximately nine o’clock this morning.” Yan Qing set down the small scalpel.

Shi Ting reached into the upper pocket of his leather jacket and produced a gold pocket watch. His expression tightened. “The train’s first stop was Qingshan, arriving at eight o’clock, with a five-minute layover. From eight-oh-five until now, the train has not stopped at any station. Which means — the killer is still on board.”

Yan Qing wiped the blood from her hands. She was genuinely impressed by how swiftly he had put the pieces together. “The train is due to reach the next stop, Miaodong, at eleven-thirty. Director Shi, you have less than twenty minutes to identify the killer.”

Once the train stopped at Miaodong, the killer could simply vanish into the crowd. Finding him after that would be like searching for a needle in the ocean.

“But all we know right now is that she was strangled, and that the killer is most likely her husband,” Bai Jin said, feeling at a loss. “There’s no concrete lead to go on. How are we supposed to find one person with no distinguishing features among ten carriages full of passengers?”

“There are leads.” Shi Ting said suddenly. “The killer has three identifiable characteristics. That should cut our search area in half.”

Yan Qing looked toward the tall, striking man with curiosity, appreciation rising in her eyes.

—