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

Inside the red zone, the child was still on oxygen. A middle-aged man, whose wristband had just been put on, clutched his chest and muttered, "I really only picked up one bite with my chopsticks."

Nurse Zhao had barely touched the chair when she stood up again, speaking much faster than before.

"Don't hang up on the platform." Sun Zhiqiang reached out and took the receiver. "Search the rider, the gatekeeper, and the person who placed the order together. First, ask who has the package and whether the box has been opened."

Ma Hao casually pressed the speakerphone button.

The first person on the other end of the phone was a customer service representative from the platform. They spoke so fast it was like a machine gun, and you could tell they were afraid of taking responsibility.

"The order shows as delivered, but the rider said it was left at the security booth at the north gate of Dongyuan Community. The recipient's phone is constantly busy. We are calling the rider back."

Sun Zhiqiang didn't discuss the procedures with her.

"Don't explain the process yet, just bring the rider in."

A few seconds later, a young man's voice came through, accompanied by the screeching sound of an electric scooter braking in the background.

"Doctor, I just finished my next delivery. I remember that one, the transparent box, I put it on the windowsill of the security booth, and the note definitely said to leave half for the child. I even took a picture."

Lin Ye paused for a moment when he heard the words "window sill".

People come and go on the windowsill.

When that box of food was sitting there, nobody knew it wasn't mixed with salt.

Sun Zhiqiang asked, "Can the photos be posted on the platform immediately and then forwarded to us?"

"Yes, we can send it now."

The sound of someone pressing a cell phone came from the other end of the line.

Ma Hao stared at the "takeout" section and couldn't help but ask, "Teacher Sun, should we just call 120 to the neighborhood?"

"First, find the right people," Sun Zhiqiang said. "Don't send a whole carload of people to their homes, only to find the boxes already inside."

Nurse Zhao had already turned around and called for the triage nurse.

"Dongyuan Residential Area, North Gate. Note the location first. Also, add a note to the 120 emergency center: suspected to be from the same source of takeout, a child may have eaten there."

The triage nurse responded and scribbled rapidly in her notebook.

Lin Ye added four words next to the temporary list: East Garden North Gate.

We won't write down the name of the illness yet, and we haven't even gotten the phone number or house number.

The platform quickly connected to the gatekeeper's phone number.

The first voice on the other end of the phone was a man with a local accent, who sounded a bit impatient.

"Feed? What's wrong now?"

The platform's customer service quickly explained, "Sir, we just left a takeout order at the security booth at the North Gate of Dongyuan. There might be a risk of food poisoning, so we need to check if the order is still there."

The guard paused for a moment.

"Takeout? They put out so many orders at the north gate every day, which one are you talking about?"

Sun Zhiqiang answered very quickly.

"Transparent box, cold beef salad, with a note saying to save half for the kids. I just put it on the windowsill."

The gatekeeper finally realized what was happening.

"Oh, that one, it was taken by a woman. She was wearing pajamas and slippers, and she was with a little girl."

Ma Hao held the pen, unsure whether to write "three buildings" or "five buildings," and didn't dare to continue.

Nurse Zhao looked up and answered.

How old is the little girl?

The gatekeeper became even more impatient.

"Who can tell? Seven or eight years old, I guess. Wearing a pink backpack. The kid even asked, 'Mommy, did you buy me meat?'"

The child's father was sitting at the entrance of the red zone when he heard the words "little girl," and he almost dropped his phone.

"I also have a daughter." His voice was terribly hoarse. "My mom hasn't answered the phone yet."

Nurse Zhao didn't scold him; she just pushed the phone into his hand.

"Keep hitting. Hit your mom, hit your neighbors, hit the property management, hit whoever you can."

The child's father nodded, then flipped through his contacts twice, making the mistake.

The security guard was still talking on the phone.

"She seems to live in building three, or maybe five. I saw her walk inside."

Sun Zhiqiang immediately followed up, "Is there a residents' group chat? What's the property management's phone number?"

"Yes, we do, but what are you doing? How big of a problem can a box of vegetables cause?"

The guard was still muttering on the phone when a muffled groan suddenly came from the red zone.

The middle-aged man, who had been so defiant just moments before, was now half-supported on the edge of the bed, his other hand pressed tightly against his chest, and he could barely speak.

The nurse had just put on the ECG leads when she glanced down at the monitor.

"Teacher Sun, your heart rate is 126, your lips are still purple, and your pulse oximetry reading is not good either."

Sun Zhiqiang glanced back and immediately spoke into the phone.

"That's not an ordinary dish. Don't ask how serious the situation could be yet. First, send a message in the group: 'Don't eat cold beef salad. If you've already eaten it and your lips turn purple, you feel chest tightness, dizziness, or nausea, call 120 immediately.' Just send these few sentences, don't change them yourself."

He silenced the guards at the gate after he spoke.

Two seconds later, I heard the sound of someone searching for a pen.

"Slow down, let me write this down."

Lin Ye suddenly spoke.

"One more thing: don't induce vomiting, and don't force yourself to drink water."

Sun Zhiqiang glanced at him, didn't ask any more questions, and simply repeated the message into the phone.

"Don't induce vomiting, and don't force yourself to drink water. If you have children at home, first check their lip color and overall energy level."

The gatekeeper muttered something.

"Does lip color matter too?"

Nurse Zhao interjected, her tone curt.

"Just send it when I tell you to. Don't wait until everyone in the group is asking questions and you've already got someone lying on the ground."

This time, the gatekeeper didn't argue back.

The sound of typing came through the speakerphone, intermittently.

The platform's customer service representative said, "We got through to the person who placed the order, but she said her child had only eaten two bites and was fine."

Lin Ye looked at Sun Zhiqiang.

"Bring them in."

Sun Zhiqiang didn't have to repeat himself; the customer service representative had already transferred the call to him.

The first thing I heard on the other end of the phone was the sound of a television, followed by a woman's panicked voice, and a child's drawn-out, coquettish voice.

"Doctor, I really don't know anything about poisoning. We only ate two bites, and my daughter even complained that it was too salty."

Sun Zhiqiang asked very directly.

How old is the child?

Eight years old.

What color are your lips?

The woman remained silent for a long time.

"Lips? Well, normal lips."

Lin Ye didn't interrupt.

Sun Zhiqiang continued, "Go to the child now and see him for yourself. Don't shout from across the living room."

I could hear the sound of slippers stomping on the floor from the other end of the phone.

The woman called out, "Xixi, come here and let Mom take a look."

The child is not happy.

"I still have homework to do."

The woman's voice was a little distant.

"The doctor wants to check my mouth."

The emergency room alarm sounded twice, but there was still silence on the other end of the phone.

When the woman spoke again, her voice trembled at the end.

"Why do her lips look a bit grayish? It wasn't this noticeable before."

Sun Zhiqiang immediately asked, "Do you feel dizzy, have chest tightness, or nausea?"

The child's voice came through the phone, small and delicate.

"Mom, I feel a little nauseous."

The television was still on, and it sounded particularly jarring.

The woman was so flustered that her words were all jumbled together.

"Is it just psychological? She mentioned feeling nauseous today when she didn't finish her homework."

Nurse Zhao rolled her eyes, but swallowed the words she was about to say.

Sun Zhiqiang said, "Don't gamble on whether it's just psychological. Do three things now: don't touch the food container, keep the child seated and don't let them run around, and call 120 immediately. Give them the address clearly: which building and unit in Dongyuan Community."

The woman's breathing became erratic.

"My husband isn't home, and I'm taking care of her alone. Could I drive there myself?"

Lin Ye spoke directly.

"Don't drive yourself. If the child vomits or gets dizzy on the way, you won't be able to take care of them by yourself. Call 120 first and have an ambulance come and pick them up."

Sun Zhiqiang then added a sentence.

"Listen to him. Don't hang up the phone. We'll also notify the command center. Just give us your address clearly."

Sisi's mother was already crying.

"Don't cry, Sisi, Mommy will make a call now."

The child whispered, "I didn't cry, I just feel a tightness in my chest."

The moment the child uttered the words "my chest feels tight" from the speakerphone, the child's father, standing at the entrance of the red zone, jumped up, only to be pushed back down by Nurse Zhao.

"Sit down. Someone is watching your child."

The child's father was clutching his phone.

My daughter is home too.

"Then keep calling." Nurse Zhao shoved the phone back into his hand. "If he doesn't answer the first one, call the second. You're not the only one in the emergency room."

The child's father lowered his head and continued dialing.

Sun Zhiqiang had already picked up another phone and dialed the 120 command center.

"An eight-year-old child ate two bites of this takeout from the north gate of Dongyuan Community, and now his lips are grayish, he feels nauseous, and complains of chest tightness. It is suspected to be nitrite poisoning. Send a car over, provide oxygen on the way, and keep him under supervision. Do not let the family drive themselves."

After giving the address, he turned to look at Lin Ye.

"Where has the list of patients with mild symptoms been taken?"

Lin Ye glanced at the temporary list.

"18 people have arrived at the hospital, 4 are on the 120 bus, and the Dongyuan family has a new child. There are still two cash payments left that haven't been confirmed."

Ma Hao looked up.

"One of them bought it with cash, and nobody knows who it was. The cold noodle stall next door said it looked like a man in blue overalls who rode away on an electric scooter."

Nurse Zhao gave him a disapproving look.

"It looks like a man, riding an electric scooter. If you add 'looks like a human,' you can find him all over the city."

Ma Hao swallowed the second half of his sentence.

"I'm just repeating what they said verbatim."

"We need to get their exact words." Lin Ye looked at the list. "Are there any labels? Are there any delivery boxes? Are they bringing children? Which way are they going?"

Ma Hao turned around and ran back to the phone.

In the red zone, a section of the middle-aged man's electrocardiogram paper was spilled out.

The nurse tore it off and handed it to the second-line doctor.

The second-tier doctor glanced at it.

"Proceed with the poisoning diagnosis first. Don't forget the ECG changes if you experience chest tightness. Also, schedule a repeat blood gas test."

This time, the middle-aged man didn't try to be brave and asked in a low voice, "Doctor, is this also quite troublesome for me?"

Nurse Zhao pressed his hand back against the bed rail.

"If you know it's going to be troublesome, then don't do anything rash. I just asked you to put on the wristband, and you complained that it was too much trouble."

The man shut his mouth.

The platform's customer service representative was still online at the triage desk.

"Doctor, the person who placed the order at Dongyuan said there's half a box left, and she's already put it on the kitchen counter."

Sun Zhiqiang responded quickly: "Tell her not to pour it out, not to wash it, and not to throw it away. Keep the outer packaging, chopsticks, and leftovers. We'll wait for the market regulators to collect evidence, and the CDC may also need to take samples."

The customer service representative cautiously asked, "Should our platform notify all orders with the same payment method?"

"Yes," Sun Zhiqiang said. "Don't wait for us to chase them down one by one. You should send them the order notifications and make phone calls. Keep the messages simple, don't write a bunch of nonsense about liability. Just tell them not to eat it, and if they have symptoms after eating it, call 120 or come to the emergency room."

Lin Ye listened and added the words "Platform Notification" after the takeout section.

The light blue notification from the beginning reappeared before his eyes.

The person on the emergency bed was being watched over, but the boxes that had been packed up and taken away were still in various kitchens, guard posts, and on the road.

On the other end of the phone, Sisi's mother's voice came through again.

"Doctor, my daughter says her hand is numb. The ambulance hasn't arrived yet."

Sun Zhiqiang looked at the triage nurse.

The triage nurse is already urging the 120 emergency center.

The automatic door outside the red zone opened again, and the night breeze swept in, carrying a slightly damp chill.

Lin Ye's gaze fell back to the column of blue work clothes.

Just then, the light blue text in the corner of my vision lit up again.

[Risk Clue: Cash being taken out.]

[Key issue: The whereabouts of the blue overalls are unknown.]

[Important Note: Those who have consumed this product may experience rapid onset of chest tightness, cyanosis (bluish discoloration), and decreased consciousness.]

Lin Ye looked up.

"Teacher Sun, we can't wait for the platform. Let 120 ask the vendors on site and the stalls next to us: are they wearing blue overalls, riding electric bikes, do they have brand license plates, and which road do they go?"

Sun Zhiqiang glanced at the blank spaces on the list, then scanned the speakerphone that hadn't been disconnected yet.

"Ma Hao, don't let the call drop," Sun Zhiqiang said. "Go after the guy in the blue overalls."

Ma Hao had just put the receiver back to his ear when his voice became even more strained than before.

"Teacher Sun, the ambulance from the East Campus has arrived."

On the phone, the woman cried out.

"She vomited! Her lips turned even grayer!"

Immediately afterwards, the 120 emergency medical personnel took the call.

"The First Municipal Hospital, East Campus, has picked up the child. He is still conscious, but has chest tightness, is vomiting, and his lips are grayish. We will be there in ten minutes."

The ambulance operator added another sentence.

"Also, the security guard said that the guy in the blue overalls has been found. He didn't go home; he rode his bike to the entrance of the community and sat down on the ground, with half a box of cold beef salad next to him."