When I'm on the night shift, all the department heads can't sleep.

"Give me the gatekeeper's phone number."

Ma Hao wrote down the number and immediately dialed back using the landline next to the triage desk.

A few seconds later, the call was connected, and Ma Hao first identified himself.

"Emergency room at the First Municipal Hospital. Did you find the person in the blue overalls riding the bicycle that we asked you to find?"

They didn't even bother with pleasantries at the gate.

"Found him, he's sitting on the steps at the entrance of our community."

The wristband on Nurse Zhao's wrist was only halfway applied, with the edges still sticking up.

She looked up at the person asking the question: "Is the person still conscious?"

The gatekeeper sounded like he had just run back from outside, still panting as he spoke.

"He agreed when I asked him, but he kept saying he felt tightness in his chest and wanted to vomit. His lips were a little purple. There was also half a box of cold beef salad next to him, but he wouldn't let me touch it, saying that he had paid for it and that he would have to argue with the stall owner later."

Sun Zhiqiang took over the conversation immediately.

"Don't let him take the box, and don't spill the food. Let him sit down, don't let him stand up, don't let him drink water, and don't let him induce vomiting. Before the ambulance arrives, just check two things: whether he responds to your calls and whether his lips are even grayer."

The gatekeeper was in a panic.

"I'm just a security guard, how would I know about that?"

"You have to watch even if you don't know," Sun Zhiqiang said emphatically. "You're the closest to him right now."

The gatekeeper choked on his words, and only responded after two seconds.

There's no time to catch your breath in the emergency room.

The boy from the night market had just had his oxygen tube changed, and the pediatrician hadn't even sat down. The middle-aged man who had been so stubborn was being pushed back against the bed rails by the nurse; the ECG leads weren't even properly attached yet, and he was already asking again when he could leave.

The triage nurse covered the other stethoscope and passed the message over to this side.

"The young girl from Dongyuan is already in the car, heading towards the hospital. Sister Guo and her husband just got in the car too; they said the husband was vomiting badly."

No sooner had those words been spoken than the phone next to the triage desk rang again.

The triage nurse listened for a few words and then immediately turned around.

"Teacher Sun, the bus from the East Campus is almost here. The next bus from the blue uniform side is another seven or eight minutes away."

Unfortunately, there was only one bed left that could be vacated immediately in the red zone.

Nurse Zhao looked up at the speakerphone.

"Seven or eight minutes? Can he sit still?"

Lin Ye didn't interrupt immediately, his gaze falling on the column for blue work clothes.

In the corner of my field of vision, pale blue lettering flashed briefly.

[Risk Clue: Blue overalls.]

[Key issue: The person is still at the entrance of the residential compound, and the vegetables haven't been sealed yet.]

[Clues that can be followed: gatekeeper, half a box of leftover food, photos of the scene.]

Lin Ye looked up and asked the attendant, "Master, who's watching that box of vegetables now?"

The guards didn't react in time.

"what?"

"Is he still holding the box, or has he already put it down?" Lin Ye asked, speaking faster.

The guard seemed to have moved his phone away, and shouted a couple of times towards the other side, including a sentence in between: "Don't touch that box yet."

When he returned, his voice had changed.

"It's still at his feet. He said it's evidence, and no one can touch it."

Ma Hao was copying when the words on his wristband slanted out a bit.

"Still using it as evidence?"

Nurse Zhao looked up at the speakerphone, her voice still tinged with anger.

"Even in this situation, you're still thinking about picking a fight with someone."

Lin Ye recalled the fifth bed at the construction site a few days ago.

My ankle was so swollen I couldn't even wear shoes, but I was still clutching the toolbox key, afraid I'd be in trouble if I was missing a wrench.

The blue overalls protected the half-eaten box of vegetables, probably because she was afraid of not being able to explain herself.

But this thing can't be touched by anyone anymore.

Lin Ye looked at Sun Zhiqiang.

"Teacher Sun, we can't just pick up people."

Sun Zhiqiang turned to look at him.

"Don't leave things unsaid, why?"

Lin Ye pointed to the column for blue work clothes on the list.

"There was a paramedic in the car with the child, and the one experiencing chest tightness was right under our noses."

He glanced at the bed in the red zone and then finished the sentence.

"The man in the blue overalls is still outside, with only one guard nearby. He's already feeling unwell, and half a box of vegetables hasn't been sealed yet." Lin Ye spoke slowly, but emphasized each word more than before. "If he really faints, it'll be hard to say who took the box or who touched it."

Ma Hao was the first to react, and he picked up a pen and pointed to the blue work clothes section.

"That means the person has to be put on the vehicle first, and the box also has to be kept under surveillance."

Nurse Zhao turned around and added a sentence to the triage nurse.

"Let the gatekeeper take photos first, don't move anything. Those watching should also keep others away, and nobody should reach out."

Sun Zhiqiang didn't nod immediately; he first scanned the red zone.

The emergency room staff were handing the boy's medical orders to a nurse when they heard what was being said, but they didn't even look up.

"I'll keep an eye on these two in the hospital. If the one with chest tightness comes back from his follow-up appointment, just call me."

The pediatrician took the suction tube from Xiao Zheng and added a comment.

"When the child from Dongyuan arrives, push him towards me. Don't let his family rush in with him. The person outside, put him in the car first. Leave the leftovers and the containers where they were. Don't let anyone take them back and forth."

Sun Zhiqiang then picked up another phone.

"Is this 120? The guy in the blue overalls at the entrance of the complex is having chest tightness and feeling drowsy. Call the emergency number first. See which car is closest and if we can turn around and go there."

He paused for a moment, then clarified his words.

"Tell the gatekeeper not to leave. Have him watch over that half-eaten box of vegetables, make sure it's not thrown away, not washed, and not touched by anyone else. Take a picture first, clearly showing where it's placed. We've called the duty officer here, and we've also notified the local authorities and market supervision department. They'll seal it off once they arrive on site."

The command center responded quickly.

At the entrance to the red zone, the father of the boy from the night market suddenly looked up.

"What about my daughter? She's at home too!"

As soon as he raised his voice, several family members from the night market looked over.

Nurse Zhao pressed the newly applied wristband onto the table.

"Don't panic. Your son is in bed, and the pediatrician is right there. He's not unattended."

"Keep calling your daughter. Once you get through, ask her if she ate that box of vegetables. If she didn't, tell her family not to touch it. If she has already eaten it, or if she's feeling unwell, call 120 immediately."

The child's father held his phone and glanced into the red zone.

The pediatrician is securing the child's face mask, Xiao Zheng is bending over to watch the suction tube, and the emergency second-line staff are standing at the foot of the bed checking the doctor's orders.

He moved his lips, then lowered his head to continue dialing his home phone.

Nurse Zhao muttered something as she turned around.

"Everyone's in a hurry. But if one person is missing now, it won't just be a matter of one bed anymore."

Ma Hao had just put down his pen when she glanced at him.

"Is the wristband finished writing?"

"Write it, write it right now."

The first ambulance arrived first.

The automatic door opened, and the girl from the East Garden was pushed off. She was curled up on the gurney, her face pressed against an oxygen mask, her eyes still open, but her cries were weak.

Her mother followed beside her, carrying a transparent takeout box. Before getting on the ambulance, she was told to bring the leftovers, chopsticks, and outer bag. The lid of the box was wrapped with tape, and there was still half a box of cold beef salad inside, with chili oil clinging to the sides.

"Doctor, I didn't fall over," Sisi's mother hurriedly explained upon seeing the white coat. "The chopsticks are still here, and the bag is still here. I really didn't know she would do this."

Nurse Zhao did not take the box.

"Don't hand it to me yet, put it in a sealed bag first. Write down who brought it and what time they arrived, so there won't be any misunderstandings later. You and the child go, don't explain here."

Sisi's mother had red eyes.

She only ate two bites.

The pediatrician pushed the stretcher toward the child monitoring area.

"Two bites count as eating. Take care of the child first, don't keep explaining."

Lin Ye followed and took two steps.

The girl's lips were a grayish-purple, her eyelids were half-closed, and one hand was still clutching the cuff of her school uniform. Her mother bent down to hug her, but was stopped by Nurse Zhao.

"Don't lie on top of her. Stand to the side and answer whatever the doctor asks."

The girl from Dongyuan had just been connected to her guardian when the triage desk called again.

"The car in the blue overalls has arrived at the entrance of the residential area!"

Sun Zhiqiang turned around.

"How is he now? Can we wake him up?"

The triage nurse pressed the stethoscope to her ear while reaching for the logbook with her other hand.

"He's sleepy, but he can be woken up, though he's slow to respond. The gatekeeper said he's still guarding that box and won't let anyone touch it."

Nurse Zhao put the registration book in her hand on the table.

"Even after all this, you're still protecting the evidence."

Ma Hao whispered a reply.

"Perhaps they're afraid they won't be able to explain it clearly."

Nurse Zhao glanced at him but didn't respond.

Lin Ye said to the triage nurse, "Ask the gatekeeper again, has the photo been taken? Are there any people gathered around?"

The message was quickly relayed.

The guard shouted a few times, and when he replied, his tongue was practically tied in knots.

"The security guard said that the photo had been taken, and the people around had also stopped the box, but it's still in the same spot."

Lin Ye looked at the column for blue work clothes on the list and didn't scroll down any further.

As long as the half-box of food is still there, there's still someone to hand it over.

"Get the person into the car first," Lin Ye said. "Don't move the box, keep the photos safe, and watch over the place. Don't let anyone else crowd around."

Sun Zhiqiang took the second half.

"Don't move anything before the authorities arrive. Call the CDC too, they'll need to investigate who ate it and where it came from, so keep their phones on. Give them oxygen on the way, connect them to monitoring if possible, and report their blood pressure and level of consciousness before they arrive at the hospital. Report their pulse oximetry too, but don't just focus on that number."

Before the call was even over, the blood gas analysis report arrived at the ER's second-line team.

He glanced at it and handed it to Sun Zhiqiang.

"This adult in the hospital is experiencing chest tightness. Their methemoglobin level is 28.1, and their lactate levels are also high. Don't keep them in the mild case ward; move them to the red zone."

The middle-aged man's wife quickly grabbed the bed railing.

"He just said he felt better."

Nurse Zhao helped her up.

"He just said his face is naturally purple. Don't believe his stubbornness now, just go with him."

The bed that had just become available in the red zone was moved over.

The sound of stretcher wheels came from the doorway again.

We just picked up one patient in the red zone, and the triage desk is already calling for another one.

The nurses' station list was revised several times over; before all the old names were even crossed out, new calls came in.

Sun Zhiqiang glanced at the nurses' station; the glass of water beside him was still full.

"Lin Ye, of those who took them away, how many are still missing?"

Lin Ye looked down at the list.

Payment records, verbal statements of cash transactions, platform notifications, and responses from security guards are all crammed onto a single sheet of paper.

He rechecked the few confirmed entries and found only one blank space remaining.

"One item," Lin Ye said. "Cash, no payment record. They said an old lady bought it and walked towards the bus stop."

Nurse Zhao turned to the next line in the registration book.

Bus stop.

Sun Zhiqiang immediately responded.

"Keep chasing. Ask which bus it was and what time it left."

Ma Hao picked up the phone again and continued to press for answers.

"The ambulance said that someone at the nearby stall remembered her; she boarded the last bus."

Ma Hao listened to the license plate number being announced and quickly looked up.

"The license plate has been found, and the person may still be on the bus. The bus dispatcher is contacting the driver."

Sun Zhiqiang immediately spoke up.

"Tell the driver to pull over and don't let anyone in the car touch that bag."

A few seconds later, the bus dispatcher answered the phone and immediately reported the result.

"We've contacted the driver. He said there was indeed an old lady in the car, carrying a yellow bag. She had just shared a piece with a child next to her."