Sirius squinted at the footage and let out a sharp laugh.

“Ah… our CCTV officer’s effort is as reliable as Fitta’s budget. No wonder everything looks half-broken.”

He slowed the playback. At 2:00 a.m., the ginger-haired nurse appeared on the second floor. At 2:10, the same guy showed up on the fifteenth.

Sirius leaned closer, eyes narrowing.

“But before he enters the thirteenth floor… he vanishes. No hallway, no shadow—just gone.”

Zoro’s eyes bulged, lips stretched into a clownish grin, arms flailing like a marionette.

“A ghost? A phantom? He… just disappeared. The thirteenth floor… how is that possible?”

Lihar rolled her eyes, deadpan.

“Please. Even a ghost wouldn’t survive Fitta’s standards.”

Sirius grinned, waving a hand theatrically.

“Ah, don’t insult our motherland like that! If I can live here, it can keep anyone—ghosts included.”

Kyrokuto’s deep voice cut through the room.

“Sirius, focus. Save the theatrics for later.”

Sirius raised a hand in a sharp salute.

“I’ll make things easier—Nilo, come forth.”

Nilo swiveled in his chair, grinning wide.

“Aye aye, captain.”

Nilo was eighteen, with wavy blond hair cut in a loose wolf style that peeked out from under the hood of his sweatshirt. Big blue-and-black glasses framed sharp, observant eyes, giving him the look of someone always calculating, always three steps ahead. He had no degrees, no official credentials, but since Sirius wasn’t as serious as his name might sound, he had hired him years ago. The Department of Detectives had no idea that Nilo worked for them—an unofficial prodigy hidden in plain sight.

Nilo’s fingers danced over the keyboard, pulling up the CCTV feed and adjusting the focus with a few precise commands. He applied a quick digital zoom on the nurse’s badge—just enough to make it legible. There it was, clearly printed: Kiko.

“Certainly, you can do much more, kid,” Kyrokuto said while leaning back on his chair.

Nilo typed a few rapid commands, slipping past firewalls and probing the government ID system. Within moments, he pulled up Kiko’s complete history—shifts, access logs, and movements—everything neatly mapped on his screen.

A small pop-up appeared with the details: Kiko Bilton, age 30, working here since 24. Status: married, one child.

Sirius stood up and headed toward the door, a hint of Stella’s whining still lingering in his eyes.

“Lihar, Zoro, Uncly—let’s go and have tea with Kiko.”

Zoro’s lips stretched into that clownish grin again.

“Finally, a proper introduction!”

Lihar brought a hand to his face, rolling his eyes.

“Tea with the ginger ghost… why do I even agree to these things?”

Nilo didn’t move from his seat, fingers still hovering over the keyboard.

“I’ll be undercover. Call me if you need me.

At the hospital 

Sirius glanced around the corridor, then turned to Zoro.

“Zoro, go and borrow nurse kiko for us.”

Kyrokuto, already moving, called back,

“I’m on the second floor.”

Lihar shot a look at Sirius.

“So I’m stuck with you on the thirteenth?”

Sirius adjusted his collar and sleeves, as if ready for action.

“How lucky of you!”

They both marched toward the 13th floor, eyes serious, the previous amusement wiped away.

After taking the stairs, they reached the corridor door of the 13th floor. Inside was the IT room—a smaller version of the one on the fifteenth floor.

“Do you see where Kiko, the ghost, goes?” Sirius asked, scanning the room.

“More like Kiko, the technician,” Lihar replied, sliding on his unforgettable granny glasses.

A few minutes later, Nilo’s voice came through the phone.

“ Captain. I’ve traced every IT-linked system on each floor.”

The screen flickered to life with a digital map: floors lit up, AC units, vents, cameras, and sensors—all color-coded.

“Every system here is connected to the IT room on its floor,” Nilo explained. “ACs, security feeds, some environmental controls… you name it, I’ve mapped it. You’ll see exactly what each system can do, and where it’s linked.”

Sirius leaned closer, studying the map.

“So far, nothing jumps out… but we have the blueprint. That’s what matters.”

Lihar scanned the screen.

“There’s something… this isn’t on all the floors.”

Sirius’s eyes followed the highlighted units, and at the same instant, both of them said:

“Air conditioners.”

They looked at each AC unit in turn, nodding, the pattern sinking in.

“Only five in the whole hospital,” Lihar said. “Two on the third floor and three on the fifteenth.”

Sirius lifted a hand and swept it back through his hair, a habitual gesture whenever he sank into deep though

“The culprit knew this hospital too well.”

Zoro appeared at the doorway, Kiko slung casually over his shoulder, arm draped around his neck.

“Not only the hospital… but also Kiko,” he added, a grin spreading across his face.

Kiko wore a surgical mask—he had a mild cold, and exposure to patients could be dangerous. His orange hair peeked from under his cap, and his strong Thai accent marked every word he spoke.

Nothing seemed off during the questioning, but when Lihar asked, “Do you usually get praised for your work these days?”

Kiko gave a small, almost sheepish smile. “Quite a lot. At first, I found it strange… but the work I’m assigned gets done fast, and people actually appreciate it, so I went along with it.”

Sirius caught Lihar’s gaze, a spark of mischief in his eyes.

“Are you thinking what I’m thinking?”

Lihar gave a bombastic side-eye, the kind that screamed criminal offense.

“Absolutely not. I’ve got no idea what goes on in that lunatic brain of yours."

Sirius smirked, a gleam of satisfaction in his eyes.

“Well, my friend, as crazy as I might sound… the case is solved.”

“Time for Who Wants to Be a Millionaire! Question one,” Sirius announced, a mischievous glint in his eye.

“What is senseless, invisible, odorless, but fatally deadly?”

Lihar suddenly turned toward Sirius, eyes wide.

“It couldn’t be…”

“Oh yaaasss! It is the one and only—”

“Invisible Ninja!” Zoro shouted, grinning like a two-year-old with unearned excitement.

“You fool! No!” Lihar slapped his forehead.

“It’s helium gas,” he added with finality.

Sirius pointed at him, grinning.

“The chemistry lessons on the fourth floor finally paid off.”

“And the winner is… DT Liharrrrr!” Sirius continued, pointing triumphantly.

From the corner, Kiko stared, utterly incredulous. What in the Fitta?? How did these guys even graduate high school? 

Police station 

“Finally, you caught the culprit,” said their mother, her voice daunting and firm.

“My little brother should be avenged,” added the brother, calm but tinged with sadness.

“Wehan… he was my friend, and—”

Sirius continued, glancing at Lihar. “You admired him for his bravery. Friends are there for each other in difficult moments, despite silly arguments. So were you.”

Lihar gave a shy, small smile, feeling the weight of the words.

Kyrokuto stepped forward, his voice heavy and commanding.

“After the analysis of all the evidence, the patterns, and other things… it is clear that Kael Sauvez is the culprit.”

Without hesitation, two officers stepped forward and handcuffed him. Kael’s expression remained unreadable as they led him away.

“It can’t be! You’re taking away my son!” their mother cried, her voice cracking with anguish.

“Mother, it’s alright… it must be some kind of misunderstanding,” Kael said, his voice trembling beneath the mask of calm.

“I’m sure you’re the misunderstanding,” Lihar muttered, arms crossed.

“Let’s keep it cool,” Kyrokuto cut in, his tone sharp as steel. He turned to Sirius. “Explain.”

Sirius exhaled, ran a hand through his hair, and spoke.

“Kael disguised himself as Kiko. He wore the mask, the wig, the uniform. From the IT room, he set up the helium to flow through the hospital’s air system. Slowly, quietly, it was released—no one could see it, no one could smell it.”

He paused, his eyes fixed on Kael.

“But then… Mother came. You panicked. You forgot to shut the system off. You rushed to fix it, but in that hurry—you forgot something else. The inhaler. It slipped from your pocket.”

Sirius’s voice hardened.

“And that mistake, Kael, is what exposed you.”

Kael straightened, his voice sharp, almost desperate.

“You have no evidence it was me! It could be anyone—anyone wearing that mask, anyone using the system the same way!”

Sirius’s gaze didn’t waver. He ran a hand back through his hair, his voice calm and precise.

“Only one person forgot to pick up the inhaler that night. But also—no one else worked here for five years alongside Kiko. No one else knew his shifts, his habits, his routes through the building.”

Kael’s jaw tightened.

Sirius leaned in just slightly, eyes narrowing.

“And in your childhood photos—you were always playing football. Fast, fit, agile. Exactly the kind of training that let you slip between floors unnoticed.”

Lihar’s eyes sharpened, his brows dropping low.

“Jealousy,” he said flatly.

Sirius continued, his tone cutting sharper.

“And then there’s Capital Low Market Streeton. You thought you were clever buying the wig there, but the shop had cameras. That footage caught you.”

The words struck like blows, each one cornering Kael further, until the room grew silent enough to hear his ragged breath.

Kael’s head dropped, his whole body trembling. Then, the dam broke. Tears streamed down his face as he shouted, the words spilling raw and jagged.

“I was taller… stronger… My childhood dream—football. I played every day after school, I won those medals, I gave it everything. And what did he do? He tossed them aside. Said they meant nothing.” His voice cracked, bitter and broken. “He told me he worked hard so that I could become a doctor. That all his sacrifice meant I had no right to choose.”

His sobs came harder now, his chest heaving. “But when it came to my brother? Oh, then it was alright. Because he was naturally talented. He didn’t have to prove himself. He didn’t have to bleed for it. He was allowed his dream… and I was chained to his.”

Kael’s voice shattered into silence, the weight of years of anger finally laid bare.

Kael’s sobs tore through the room, but before he could say more, a sharp crack echoed—his mother’s hand across his face.

“You fool!” she cried, her voice trembling with rage and grief. “He believed in you! Don’t you understand? He never trusted your brother’s intelligence—he feared it would fail him. But you… you were the one he placed his hopes on!”

Her tears streamed as her words cut deeper than any blow. “He wanted you to have a good life. A life without poverty! That’s why he forced you… because he thought only you could carry it!”

Kael’s face twisted, stunned—not from the sting of the slap, but from the weight of the truth he had never let himself hear.

Kael’s voice cracked as he lifted his tear-streaked face toward his mother, anguish twisting his features.

“But I had the right… the right to fulfill my dream!”

Sirius's voice dropping like a blade.

“And he had the right to live.”

The words struck harder than the slap. Kael’s shoulders buckled, the last of his defiance breaking under the weight of guilt and truth.

After Kael was taken away, the room finally exhaled.

“Ah man… that was low-key sad,” Zoro muttered, rubbing his forehead. Then his grin widened. “Which reminds me… someone else’s father also wanted them to be a doctor.”

Kyrokuto’s raised eyebrow made everyone glance at him.

Lihar leaned back, smirking. “Oh really? Rings a bell… Doctor Sirius?”

Sirius threw his head back, dramatic as ever. “Ah, but unlike some people, I followed my dream. My passion. My curiosity!” He spread his arms wide, as if declaring it to the world.

Zoro snorted. “Curiosity, huh? That explains why half your cases end with you almost blowing yourself up.”

The laughter rolled through the room, loud and chaotic.

“He’ll never change,” Lihar muttered, shaking his head.“

Sirius cleared his throat.

“Now, if anyone doubts the genius of Doctor Sirius, remember—without me, half of Fitta would still be sniffing helium and wondering why elevators don’t work!”

The room erupted all over again, Lihar groaning with exasperation, and even Kyrokuto letting out a rare, amused chuckle.

“He’ll never change,” Lihar muttered.

“And that’s why he is Sirius—the unserious,” Zoro said, patting Sirius on the head.

Sirius, unbothered responds. “Unserious… but indispensable.”