'How early? As early as when I said, "Don't forget to run tonight, okay"?'

"And then?" Cheng Shuo pressed.

"I studied until 3:30 AM. I have a 9 AM class today, so I really couldn't stay up any longer and went back to the dorm to sleep."

He took a deep breath. "He was already dead."

"What do you mean, already dead?"

"No pulse, no breathing, completely gone." The roommate pushed up his glasses, his speech a bit fast as if trying to mask his emotions with calmness. "A standard death by asphyxiation."

Cheng Shuo stared at him intently.

"When I opened the door, he... was already exhibiting 'postmortem phenomena'." The roommate paused, then added, "Algor mortis, dilated pupils, no reflexes, stiff limbs."

Postmortem phenomena, stiffness, coldness.

His mind was buzzing, as if an invisible knife was rapidly slicing through it.

"Stiff?" he asked with difficulty.

"Yes, rigor mortis begins about two hours after death and usually becomes complete in four to six hours. Based on the degree of algor mortis... the time of death was likely between one and two in the morning."

The roommate pressed his lips together, his face pale. "I should have gone back earlier. If I'd gone back earlier, he could have been saved."

Between one and two in the morning.

He recalled their conversation last night—Cen Zeng was still talking to him, still telling him "let's run tomorrow," still saying "be careful on your way."

He felt a wave of nausea in his stomach.

"How... how did you find him?" he asked again.

"The moment I entered, I saw him hanging from the railing of the top bunk." The roommate's voice dropped. "It was a typical 'incomplete suspension hanging,' toes touching the ground, knees slightly bent."

Incomplete suspension hanging.

Cheng Shuo's mind went completely blank.

"There was also bruising on his eyelids." The roommate hadn't stopped, perhaps once he started, he had to vomit it all out. "Typical postmortem cyanosis. Because the jugular vein was constricted, blood pooled, causing dark purple bruising on the head, and there can also be conjunctival hemorrhage."

He paused. "His lips were purple, his face was slightly swollen, and his tongue was protruding slightly between his teeth."

Cheng Shuo couldn't help but gasp.

"Did you try to save him?" he asked.

"No, the signs of death were too obvious, there was no way to perform first aid," the roommate said in a low voice. "The ligature mark on his neck was a complete, closed loop, a typical rope furrow, with subcutaneous bruising, and it was indurated to the touch."

Livor mortis, furrow, induration.

Cheng Shuo's mind was filled with unfamiliar medical terms, mixed with the image of Cen Zeng's perpetually indifferent, calm face.

"This wasn't his first attempt, was it?" Cheng Shuo asked in a low voice.

The roommate's fingers trembled slightly as he pushed up his glasses. "You knew?"

"He..." Cheng Shuo didn't finish. "But I didn't think it would be so soon."

The roommate took a deep breath. "I only suspected. I'd seen some faint pigmentation on his neck before, very slight, and thought it was from the sun. But could it be that it was actually an old ligature mark?"

Cheng Shuo froze. "What do you mean?"

"It means he'd tried before," the roommate said. "The mark was so faint, it must have been from a failed attempt."

Something exploded in his ears.

"He... tried," Cheng Shuo repeated slowly.

"Yes."

"But no one found out?"

"Maybe someone did, or maybe he found a way to hide it," the roommate said in a low voice. "But this time, he was determined."

Cheng Shuo's throat was painfully dry, and his fingers were ice-cold, unable to move.

"If..." he couldn't bring himself to think about it, "if you knew he couldn't be saved, why... did they still... rush him to the hospital for emergency treatment?"

"Right now..."

He opened Weibo. It didn't say he was dead; the trending topic was that he was still undergoing resuscitation. He was in the morgue, receiving thousands of completely useless prayers.

"It's just for show," the roommate said. "Just the usual routine."

"If..." he took a deep breath, "if I had gone back earlier... two hours earlier..."

He was shaking. He had finally started shaking.

With the person who had actually gone back early standing in front of him, his eyes were red, and he felt like he couldn't hear a thing.

'Why? On what grounds? What on earth was Cen Zeng thinking?'

'Weren't we just running last night?'

'Didn't we agree to continue today?'

"Did he..." Cheng Shuo paused, "did he leave a suicide note?"

The roommate was trembling, tears already streaming down the side of his face. He quickly took off his glasses to wipe them away.

"Yes." He took a deep breath. "Yes, just two words."

'Two. Two words. Two.'

"What?"

"Quite unnecessary," the roommate said. He took a deep breath and repeated, "Quite unnecessary."

'Who was he talking about?'

'Whose life was he talking about?'