Chapter 9 — Calls are not allowed to be hung up

At a quarter past one in the morning, when most of the duty room had fallen into the slow rhythm of late-night work, with only the steady sound of the ceiling fan spinning and the ticking of the wall clock audible much more clearly than in the noisy early evening hours, Dan's phone rang again.

Thirty minutes after the call with Vinh, she still had not received any news from him, and in that silence, she had time to drink two cups of diluted iced tea, go to the hallway to stand for a few minutes to wake up, then returned to the table and sat still like a statue, her eyes never leaving the phone screen, her hand from time to time unconsciously replaying the third call recording to hear the familiar tapping sound again.

— Miss...

The whispering voice was familiar, but this time there was something different, more trembling, and Dan clearly heard the sobbing between each word, as if the child had just finished crying not long ago.

— I'm here, I listen to you. Are you okay?

— I'm fine... my uncle is drunk, sleeping in the living room...

— What about your mother?

There was a moment of silence, then a smaller sob.

— My mother... my mother is in so much pain, she can't get up...

Those words made Dan's hand tighten around the pen, all her senses focused on the fragile voice ringing in the headset. She forced herself to keep her breathing steady, not letting her own panic seep into her voice.

— Is your mother awake?

— My mother... my mother moaned softly, she told me not to call anyone...

— Why did mom tell you not to call anyone?

— My mother is afraid... afraid that if my uncle finds out, he will beat her more...

Dan closed his eyes for a second, trying to suppress the lump in his throat. She had heard similar statements more than once in her eight years in the profession, always from women who believed that suffering in silence was the way to protect themselves, even though reality often proved the opposite.

— You did the right thing, you helped me a lot when you called me. Let me ask you a little more, outside your room window, do you hear any sound?

Dan asked that question not by accident. She knew that every second of conversation was both an opportunity to gather information and a thread to keep the child calm, and that environmental sounds were always something an eight-year-old could describe more easily than any other abstract concept.

— There's a dog barking... the dog next door keeps barking every night...

— What kind of barking does that dog have, continuously or one at a time?

— Bark one sound at a time, at intervals, like... woof... woof... like that.

Dan hastily wrote down in his notebook: the dog barks intermittently, not continuously. It could be that the dog is chained or confined in a small space, barking reflexively with strange sounds rather than barking in alarm continuously. She had read in training materials that each dog had its own unique barking pattern, like a kind of acoustic fingerprint, and that residents who had lived for a long time in an area often immediately recognized which dog was barking just by listening through the walls, even though they were unlikely to remember the exact house number.

She was about to ask more when another sound suddenly rang out clearly over the line, a deep, prolonged whistle, so distinctive that it was unmistakable.

Train whistle.

— Son, that sound is the sound of a train, right?

— Yes, the train passes near my house, it's very noisy, there's a train every night at this time.

Dan sat up straight, his heart beating much faster. She reached for the keyboard, quickly opened an internal application linked to public transportation data, and typed in the schedule of freight railways running through the city area. There is only one line still operating after midnight, the old freight railway running along the east side of the city, passing near Dong Lam ward before turning to the suburban freight station.

— Does that train run at this exact time every night?

— Yes, I lie down and listen to it all the time so I know that the train will come around 1:00 a.m.

That detail, combined with the whistle of the ship Dan had just heard live over the line at exactly seventeen minutes past one o'clock, gave her a more precise anchor in time and space than any positioning data from a telecommunications broadcast could provide. There was only one section of track in the entire city that emitted a whistle sound of such intensity and frequency at this exact time frame, and that section of track ran right behind Vong Thuy alley.

— You're very good, you remember that detail very well. I asked you one more question, can you see the train tracks from your room window?

— Yes, I often stand and watch the train pass by when I can't sleep.

— Is that railway line very close to my house, like just a house or two away?

— Yes, it's very close, sometimes I can even hear the sound of the wheels grinding against the rails.

Dan framed the data in his head: Lam Dien apartment building, fourth floor, bedroom window facing the train tracks, so close that you could clearly hear the sound of wheels grinding against the rails. Not all sides of the apartment building have that view, only apartments on a certain side can see the tracks, this narrows the search scope to half of the fourth floor apartments.

She pictured the building's layout in her head, a simple rectangle with a hallway running down the middle, two apartments facing the railroad tracks, the remaining two apartments facing the main alley. If it was as the child described, the search scope now only had two possibilities left, a number that she didn't even dare to dream of a few hours ago.

The child's voice suddenly became panicked:

— Aunt, my mother is moaning louder, I have to go check on her...

— Okay, go ahead, I won't hang up, just leave the phone there if you can, don't worry about me.

But the sentence was not finished, a rustling noise sounded as if the child was hastily stuffing the phone somewhere, then the line went silent, not the sound of the phone being hung up, but a long silence, as if the call was still open but there was no one on the other end of the line to listen to her anymore.

Dan kept his headphones on, not daring to hang up, just sitting there listening to vague sounds echoing: distant footsteps, something colliding, and even the sound of someone's gasps. She signaled Bao Ky to call Anh Tuyet closer, her hand still not leaving the mouse, her eyes glued to the recording screen that continued to run, each passing second was counted by the breath held in her chest.

She looked at Bao Ky and saw that he was also holding his breath watching the developments on her screen, his hand placed on his phone in case he needed further assistance. No one in the duty room said a word during that time, all they could do now was wait, and waiting in this profession is sometimes more tiring than acting.

Three minutes later, no clearer sound appeared, and the call automatically disconnected, perhaps because the phone's battery was exhausted after turning it on and off many times during the night. Dan looked at the screen, call duration: four minutes and twelve seconds, the longest of the four calls from the beginning of the evening until now, but also left her with a greater insecurity than any time before.

She took off her headphones, her hands shaking slightly as she reached for the notebook and scribbled the last line: "Mom shows signs of more serious injury, can't stand up on her own. Need to act before the fifth call comes in."

Anh Tuyet had been standing behind her for some time, placing her hand on the armrest of the chair, skimming through the words she had just written.

— It's more serious, just like I feared.

— Yes, sister. And now I have a new clue, the train whistle. I think I can use it to more accurately determine the direction of the house, even the direction of the window.

— Okay, I'll send all the recordings back to you, so we can listen more carefully and compare them with the official train time. But first, you should call and let Mr. Vinh know that the situation has just worsened, so that he will have more motivation to check more closely each door along the side overlooking the tracks.

— Yes, I'll call right now.

Anh Tuyet patted Dan's shoulder gently, then returned to her desk, her hand holding headphones ready to listen to the recording she had just received. The entire on-call room seemed to shrink around two women and a young man, all of whom were concentrating on a race against time that only they realized was happening.

Dan nodded, her hand already on the phone, but her eyes still did not leave the text she had just written, as if staring at it long enough could slow down time, enough for her to do everything on time this time, unlike five years ago.