Chapter 2 — Calls are not allowed to be hung up

— Ms. Tuyet, please listen to this for me.

Dan was standing in front of the team leader's desk before he realized he had just left his chair. Than Anh Tuyet looked up, looked at Dan's expression and didn't ask anything more, just pulled her chair closer and put on the extra headphones that she kept in her desk drawer for times when she needed to listen with someone. Dan opens the recording and drags the cursor to the exact third second.

A child's voice rang out in the small speaker, intermittently, whispering: "Auntie... help me..."

Anh Tuyet closed her eyes, listened to the entire nine-second recording, then opened her eyes and removed the headphones from her ears slowly as if the hasty movement might break something important.

— This girl didn't call the wrong number.

— I think so too. Nine seconds is not enough to locate, the number is not registered, the callback cannot be reached.

— How old do you think you are?

— From the sound of his voice, he looks about seven or eight years old. The pronunciation still has a slight lisp on the "s" sound, with "rescue" the child's speech is a bit slurred as "save the child" and not "save the grandchild" or "save me" as adults are used to.

Anh Tuyet nodded, pulled the pen out of her pocket, and lightly tapped the tip of the pen on the table in an uneven rhythm, a habit she still did when thinking. In her twenty years of sitting at the switchboard, she has listened to all kinds of calls to distinguish between a child's mischief and a call for help that was actually swallowed mid-sentence.

— Is there any background noise?

- Have. A creak, like a wooden door hinge, right before I turned off the engine. I heard it before you did, and I fell silent immediately, as if it were a practiced reflex, not just a normal startle.

— It means I'm afraid someone in the house will hear me calling.

Dan nodded and did not say more, but as soon as the words "indoor" rang out in her head, it brought up a chain of associations she did not want to face right now: a room, a door, a voice that had whispered the same thing into her receiver five years ago, then fell silent, and never called again. She gently squeezed her fingers around the glass of water to bring herself back to the present.

— What do you think you should do?

Anh Tuyet stood up and signaled Dan to follow her towards her desk. She opened the call management software and found the section "Request emergency location support via telecommunications carrier", an electronic form with mandatory information fields: phone number, call time, reason for suspicion, level of emergency.

— I'm sending a request to ping the subscriber's location right now. But you know the process, the network has a maximum of thirty minutes to respond to cases that are not known crimes, and the results are only the location of the nearest broadcast station, not the exact coordinates.

— Which area of your ward is most likely to have incorrect positioning?

— Dong Lam. The broadcast station there covers all three adjacent residential areas, and the dense high-rise buildings cause the signal to reflect haphazardly, with errors sometimes reaching seven or eight hundred meters.

Dan looked at that number, envisioning a circle eight hundred meters in diameter in the heart of a densely populated residential area, containing perhaps hundreds of apartments and dozens of small alleys overlapping each other. One child, one door, one whisper, and eight hundred meters of space to find that one door.

Anh Tuyet finished filling out the form, sent it, then turned to look at Dan with eyes that were both serious and gentle, like the eyes of a teacher looking at a former student standing at a crossroads where he himself once stood.

— While waiting for the network's response, keep your phone ready. If you call back, even for just one second, you must answer the phone immediately and don't let it ring for more than one hour.

— I know you. I won't leave the table.

— There's one more thing you have to remember. If you plan to report to the local police, you need to have at least one clear element of danger, not just a hunch. Background noises, direct calls for help, signs of being restrained, anything that can be recorded. If not, they have the right to refuse to send official forces, and I can't blame them, because police resources in the area are limited every night.

- I know. In the recording I have "Miss, help me" with the sound of the door hinge, is that enough?

Anh Tuyet thought for a moment, lightly tapped the tip of her pen on the table three times in a row.

— Enough for Mr. Vinh in the area to pay attention, but not necessarily enough for him to ask for an official mobilization order from his superiors. Just try contacting and see how the situation goes.

Dan returned to her seat, played the nine-second recording again, this time she wore soundproof headphones, blocking out all the noise around the on-call room, leaving only the child's whispering voice echoing clearly in her own quiet space. She rewound the "Aunty, help me" part for the tenth time, trying to catch every little detail: the rapid breathing behind the sentence, a very soft sound like a suppressed sob, and at the last second, a vague sound like the sound of fabric rubbing against a hard surface, possibly the child lying face down on the pillow, pulling the blanket over his head to hide the light from the phone screen.

She opened the leather-bound notebook and wrote down every detail in neat handwriting: call time, ten forty-seven; duration nine seconds; female child's voice, about seven to eight years old; The background sound is the creaking sound of wooden door hinges; ending with the sound of rubbing fabric, most likely a blanket or pillow. Below, she wrote one more line, then underlined twice: DO NOT CLOSE THE DOCUMENT.

Bao Ky glanced over from the side table, saw Dan bent over writing, so he leaned over and asked softly:

— What was it about just now that you and Tuyet talked for so long?

— A short, suspicious call. Nine seconds, unable to locate, unable to call back.

— Nine seconds, how can you be sure if it's real or if it's a child playing with your mother's phone? Last week I received exactly three calls like that in one night, all children dialed 115 and hung up.

Dan did not answer immediately. She gave the headphones to Bao Ky, letting him listen to the recording himself. After Bao Ky listened, his face looked a little confused, but then he shrugged and returned the headset.

— It sounds a bit scary, but nine seconds is too short to draw any conclusions. If Boss Long knew I kept the file open with so little data, he would have warned me.

Mentioning that name, Dan stiffened slightly, but didn't show it. She closed the notebook and set it aside, her eyes never leaving the phone screen, waiting for a call that might never come again.

— I don't mean anything, sister. — Bao Ky added, his voice softening. — It's just that my team's call processing time target has been reminded twice this month. I'm afraid that if I put too much time into one unclear case, other cases will be slow.

— I understand your pressure. But there are cases that cannot be measured in minutes and seconds of average treatment.

Bao Ky nodded, not arguing, but his eyes were still somewhat uneasy when he returned to his screen. Dan knew he wasn't wrong to worry, the switchboard received hundreds of calls every night, and not every short call contained a child in real danger. But she also knows better than anyone the price to pay if she chooses the wrong side of that probability.

A quarter to eleven, the location request form from the network still shows the status "processing", the small rotating circle next to it has not stopped. Dan looked at the timer, then looked at the silent landline phone in front of him, both of them seemed to be competing to see who was more patient.

The duty room continued its normal pace of work around her: a small fire alarm call at the night market was relayed to the fire department, and an old lady who had fallen in the bathroom was dispatched within four minutes. But for Dan, the whole room was now reduced to only one point: the phone in front of her, and the nine-second silence still echoed in her ears like an unanswered question.

At exactly ten minutes past eleven, Dan's internal mailbox displayed a new notification. She opened it and the results from the network had arrived. A map file appears, overlaying a light orange circle over the Dong Lam ward area, with a noted diameter of seven hundred and ninety meters. Inside that circle, there are three different residential clusters: an old apartment complex, a row of workers' boarding houses, and a small neighborhood of alley-front houses. There is nothing to distinguish which of those three clusters the child is in.

Dan zoomed in on the map, dragging the cursor along each small alley as dense as a spider web, trying to imagine that behind one of the hundreds of doors was a room with creaking wooden hinges, with a blanket that a child was covering his head to hide the light from the screen. She saved the map in her file, closed the secondary tablet, then sat up straight, both hands resting on the keyboard, eyes never leaving the phone.

Nothing more happened for the next twenty minutes. There was only the sound of the ceiling fan spinning steadily, the scattered sound of his colleague's keyboard typing, and a long silence that Dan forced himself to sit still and endure, not allowed to look away.