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

"Are you already home?"

Before Nurse Zhao could even tear off the wristband, her voice rose first.

The triage nurse covered the stethoscope and turned around.

"The ambulance said they were still processing the payment records on site, and they took away the same takeout box from the same stall. They were still asking if there was any cold beef in it."

The child's father was still standing at the foot of the bed, his eyes fixed on the piece of paper in Lin Ye's hand.

People had already gathered around the two private cars behind.

A woman was leaning over a car door, vomiting. The plastic bag slipped, and the vomit splattered onto the anti-slip mat at the emergency room entrance. A security guard rushed over carrying a yellow warning sign, his shoes slipping in the water, nearly bumping into a nearby trash can.

Lin Ye did not immediately walk towards the door.

He pressed the bloody note down slightly in front of the child's father, pointing only to one line.

"Don't just focus on the lungs. Look at this item, methemoglobin, 34.2."

The man couldn't understand at all; his eyes were wide open.

What do these words mean?

Sun Zhiqiang took the note from Lin Ye's hand, his voice becoming shorter.

"Some of the oxygen-carrying components in the blood have been damaged. Oxygen gets in, but the blood can't deliver it properly, causing the person to turn purple, feel dizzy, and have difficulty breathing."

The man's lips trembled slightly, and his gaze shifted from the monitor to the child's face.

The child was still wearing an oxygen mask, and the mask was fogged up layer by layer, which was quickly dispersed by the airflow.

The blood oxygen level on the screen was still stuck in the 80s.

"What if he doesn't wake up?"

"Get oxygen first. Pediatrics, emergency room second-line, and pharmacy staff are all on their way." Sun Zhiqiang didn't give any empty promises. "You stand here, hold your phone, and tell us about your table first, and the box at your house. We'll track it down from the payment records and the 120 ambulance for the other people who packed it up."

The father nodded, but his hand accidentally pressed the wrong button on the screen, exiting the payment page.

Nurse Zhao couldn't stand it and tapped his phone twice.

"Don't mess it up. The photos are here, and the payment records are here too. You're panicking, don't let your phone panic too."

The man was taken aback by her words and became obedient.

The three people in the first car have been moved to the outside of the observation area.

The triage nurses tore open the temporary wristbands one by one, making a faster sound than usual.

"Those who have eaten braised dishes and cold dishes at the stalls, and those who only eat barbecue and whose food hasn't turned purple, should go to the front of the line. People with gray lips, chest tightness, unsteady gait, children, and the elderly should go to the front."

The young man who was helped in was indignant and pointed to the side.

"I'm feeling dizzy. Can I sit down for a bit? I didn't eat much."

Ma Hao dragged the chair to the wall and turned around to add a sentence.

"You can sit, but don't run away yet. Your lips are all purple, why are you being so polite with us?"

The young man wanted to retort, but he covered his chest as soon as he opened his mouth.

"It's just so boring."

Upon hearing this, Lin Ye immediately went over.

What did you eat?

"Grilled skewers, ice jelly, and that plate of beef." The man took a breath. "I only took two bites."

"Have you been drinking?"

"Half a glass of beer."

"How can half a glass of beer make your mouth look like this?"

The man, embarrassed by the question, lowered his voice.

"I thought I had a low alcohol tolerance."

Lin Ye glanced at his wristband and then handed the words to Sun Zhiqiang.

"Teacher Sun, please add an electrocardiogram and blood gas analysis to check for methemoglobin. Those with chest tightness should not be prioritized."

After he finished speaking, his gaze fell on the medical record book in Sun Zhiqiang's hand.

Sun Zhiqiang had already heard it and nodded directly.

"If there is chest tightness, cyanosis, unsteadiness, or a child, put them in front first to draw blood and qi out of them."

Xiao Zheng emerged from the red zone, clutching two blood collection tubes in his hand.

"The child's second vial of blood has been sent. The pediatrics department said it would arrive within five minutes, and the pharmacy asked if we wanted the methylene blue sent over first."

She added, "The weight is estimated at about 24 kilograms based on bedside measurements. I've already reported it to the pediatrics department."

Sun Zhiqiang took the landline receiver.

The person on the other end of the phone was the pharmacy staff, who were clearly also in a hurry.

"Emergency room? Methylene blue?"

"Many people at the night market are turning purple, dizzy, and vomiting. The children are unconscious, with methemoglobin at 34.2 percent, and their blood oxygen levels are not rising after oxygen therapy. Emergency medications should be sent to the red zone first, and then administered after assessment by pediatricians and second-line emergency personnel."

The keyboard on the other end of the phone was clicking rapidly.

"I'll send it right away. Prepare the weight in advance, and ask about any allergies or G6PD deficiency history you can."

Sun Zhiqiang replied quickly.

"Understood. The person is already unconscious. If the test results are confirmed, proceed with the emergency procedure. Prepare medications first, and take over when the pediatric and second-line emergency services arrive."

He hung up the phone and turned to shout at the triage desk.

"Don't write the list as one big mess. Separate the list into two columns: whether you ate the cold dishes or took away. Mark those with purple lips, chest tightness, or dizziness on their wristbands. Don't mix vendors, customers, and those who took away food on the same piece of paper."

The security guard quickly wiped the ground at the entrance and then came back with his walkie-talkie.

"Teacher Sun, the ambulance said the scene is still chaotic. A few people said they were fine and took their takeout containers home."

Nurse Zhao's anger flared up immediately upon hearing this.

"Nothing wrong? Your lips are purple and you're still waiting to go home and get some sleep?"

Her words were sharp, but her hands didn't stop; she fastened a wristband on a woman leaning against the wall.

"Name. Age. Did you eat cold beef salad?"

The woman's eye makeup was smeared with tears and sweat, and she was still clutching a skewer of unfinished grilled squid in her hand.

"I was collecting money outside; I didn't sit at their table."

"Have you eaten?"

The woman froze for a moment.

"The proprietress gave me a little bit, saying it was freshly mixed."

"Dizziness?"

"faint."

"Chest tightness?"

"A little."

Nurse Zhao looked up.

"Then don't take the skewers. If you prick someone, you'll have to write another bill."

The woman then looked down and saw the bamboo skewer in her hand, and hurriedly threw it into the trash can.

Lin Ye stopped in his tracks when he heard "boss lady".

"Do you know anyone at the braised food stall?"

The woman nodded.

"I know her. Her surname is Guo, and everyone calls her Sister Guo. It's raining heavily today, so she set out all the cold dishes under the shed and is cutting and mixing them fresh each time."

"Who put the seasoning in?"

The woman sniffed.

"She put it in herself. Later, when she was too busy, her husband helped mix a whole bowl of it."

Sun Zhiqiang looked up.

"Have the seasonings been changed? Who touched the salt shaker, MSG shaker, etc."

The woman's hand, which she had just raised, froze in mid-air.

"I heard her say that the salt shaker was almost empty, and someone handed her a transparent bag, saying to use this for now."

The woman had barely finished speaking when the triage phone rang again.

The triage nurse answered the phone, listened for a couple of sentences, and handed the receiver to Sun Zhiqiang without even capping her pen.

"120 Command Center"

Sun Zhiqiang took it.

"explain."

The other end of the phone was noisy, with the sounds of wind, shouts, and sirens all mixed together.

"Is this the First Municipal Hospital? We found more than a dozen people here who had eaten at that cold beef stall. The stall owner said there was a bag of white granules that was taken away by the people who were packing up. Sales have stopped, but a few takeout orders have been sold."

Sun Zhiqiang tapped his finger on the table.

His other hand was already pointing at the security guard.

"Report to the duty officer and have them handle the case according to the protocol for foodborne cluster infections. The security department is in charge of the entrance and will also keep the on-site contact person accountable."

"Is there a takeout list?"

The person on the other end of the phone answered quickly.

"I'm transferring it from the payment records. The stall owner said he received cash for a few transactions, but he can't remember exactly."

"Don't just ask the boss." Sun Zhiqiang lowered his voice. "Trace the payment code, the takeout box, and who took the cold dish. If they've already arrived home, tell them not to eat it. If they've eaten it and then turn purple, have chest tightness, or feel dizzy, come directly to the hospital or call 120."

Lin Ye wrote on the record sheet: Shared food, cold beef salad from a braised food stall, suspected of using white granules by mistake, takeout food not fully recovered.

When writing "takeout not fully recovered", Lin Ye traced the words "takeout" again and casually added "children at home" next to it.

The father of the child at the entrance of the red zone understood "takeout," and the color drained from his face.

"My mom just said she packed a box for his sister too."

Sun Zhiqiang pressed down on the phone.

"Don't wander off now. The child is here. Call home and tell her not to eat yet, and if she has already eaten, come over immediately."

Before the man could even unscrew the bottle of water, he hurriedly started flipping through his contacts.

The pediatrician on duty arrived in the red zone.

She looked at the child first, ignoring the chaotic scene around her.

"age?"

Lin Ye immediately reported.

"Seven or eight years old, exact number to be verified. After eating cold beef salad at a night market braised food stall, he vomited, became unconscious, and his lips turned gray. His blood oxygen level did not rise after oxygen therapy, and his methemoglobin was 34.2 percent. He is currently on high-flow oxygen."

The pediatrician lifted the child's eyelids to take a look and then listened to his breathing.

"Don't move him around yet. Keep him on oxygen to prevent aspiration. Once the methylene blue arrives, check his weight, medical history, and doctor's orders. I'll stay by his bedside."

She turned to look at Sun Zhiqiang.

"I'll continue watching the children. Family members, please don't remove your masks to feed them water."

The child's father was about to unscrew the mineral water bottle when his hand froze in mid-air.

Nurse Zhao took the bottle away.

"Did you hear me? You can't feed him now."

The man lowered his head.

"I just noticed his lips were dry."

"We know you're worried," Nurse Zhao said, placing the bottle on the lower level of the treatment cart. "But feeding it now will only cause more trouble if it chokes."

Lin Ye took half a step back, giving the head of the bed to the pediatrician.

Xiao Zheng tried the suction tube, and Nurse Zhao put the bottle of water in the lower layer of the treatment cart, and the bottle cap was fastened very tightly.

The triage desk called out again very quickly.

"Teacher Sun, the second batch of names doesn't match."

Ma Hao ran over with the temporary list he had just written; the corner of the paper was damp with sweat from his palms.

"Based on payment records and verbal accounts, at least sixteen people have eaten the cold beef salad. Of those who have arrived at the hospital now, including those in ambulances, only twelve remain."

Sun Zhiqiang stared at the list.

"Four fewer?"

Ma Hao swallowed.

"There are still a few takeout orders. I don't know if they haven't eaten them or if they've eaten them but I haven't been able to contact them."

The ambulance lights outside swept across the automatic door, flashing red and white in an instant.

The few empty seats on the list were blindingly white under the lights.

Sun Zhiqiang pressed the paper down on the table.

"Go back through the payment records. Who paid, who ate together, who took the leftovers home, who's in the hospital now, who's still at home—ask them one by one."

Before the call at the triage desk had even ended, the voice from the ambulance service (120) came through the receiver.

"At the First Municipal Hospital, the staff said that the bag of white granules has been found, and the packaging does not indicate that it is table salt."