“I can’t say for certain — it’s only an inference,” Yan Qing said. “The killer knew that air entering the body’s circulatory system could harm health, but understood that a small amount would form bubbles under compression from the heart and gradually be absorbed and metabolized, causing no death. The killer needed to kill decisively on the first attempt — if the victim survived, everything the killer had done would have been in vain. That’s why I suspect the killer conducted human experiments, carefully mastering a reliable lethal dose before striking.”

Shi Ting found it hard to believe, yet at the same time he recognized a critical implication. “The killer has a medical background and is intimately familiar with the nursing school. This further supports our earlier reasoning that the killer is someone from within the school. But I have one question — all three victims showed signs of having been subjected to abuse before their deaths, yet none of them showed any signs of resistance. If the killer held a weapon to threaten them, then when the killer came to make the injection, they would have had to put the weapon down. Finding the blood vessel concealed beneath the armpit hair and inserting the needle with precision would require both hands — there’s no way to do that one-handed. Yet even after the killer set down the weapon, the victims still didn’t struggle or resist. I can’t explain that.”

“You mean the killer wasn’t acting alone?”

Shi Ting shook his head. “Based on the various traces left at the scene, it doesn’t appear to be the work of multiple people. I simply can’t figure out why all three victims would willingly submit without putting up any fight.”

“Once we unravel the mystery of that female student’s background, everything will likely fall into place.”

“The killer is deeply ruthless. I’m concerned that Luo Baomei won’t be the last victim.” Shi Ting’s expression grew grave, his voice dropping lower. “Within this chain of connected individuals, there is still one person alive and well.”

Yan Qing was startled. “Qiao Guang?”

“Ever since Qiao Guang was released, I’ve had people posted at his residence to watch over him.” Shi Ting continued, “If nothing unexpected happens, Qiao Guang will be the killer’s next target.”

“For now, all we can do is wait for the killer to come to us,” Yan Qing said, rubbing her temples. “We also need to investigate that female student’s background as quickly as possible.”

“First thing tomorrow morning, I’ll have Zheng Yun take a team to look into it.” He glanced at Yan Qing’s face — visibly worn, drained to the point of near-pallor. “You go rest in my office. I’ll handle everything else.”

Yan Qing didn’t argue. The body she now inhabited was simply too frail, and what little she had mustered just now was nearly spent.

Shi Ting brought her to his office and turned to prepare the sofa. “This is just a temporary place to rest — there’s nothing proper in the way of bedding here. It’ll have to do for tonight.”

He came to stand before her and bent down slightly. “Forgive me.”

She was light — probably no more than ninety catties. Cradled in his arms, she felt barely there.

It was not the first time he had carried her, but in this moment — alone, the surroundings quiet — she couldn’t help feeling a trace of unease. Yet his chest was broad, and even through the fabric of his uniform, warmth reached her. Some of the tension in her nerves began to ease.

“Is there any chance your legs will recover?” The words came from beside her ear, carried in his unhurried, refined voice.

Yan Qing had already settled onto the sofa. Hearing his question, she had no intention of hiding anything — she didn’t know why, but she felt a deep and steady trust in him.

“Yes,” she answered without hesitation.

“Good.” His expression carried the look of someone genuinely glad on her behalf.

Glancing toward the window, Shi Ting said, “Rest first. I’ll go make arrangements for what comes next.”

Whatever happened, the killer must not be allowed to strike again. There must be no more deaths.

—