A low, resonant thud traveled up through the soles of her feet. Caitlyn stopped in her tracks and strained her ears. "[serious]...Did you hear that just now?" Her partner Vi tilted her head, her pink hair swaying with the motion. "[surprised]Huh? I didn't hear a thing." Sun Promenade Boulevard was bustling as usual this morning. White stone buildings lined the street, and blue hex-crystals glowed faintly in the lampposts. Just this street alone was enough to show how prosperous the city of Piltover truly was. The sky was clear, and in the distance, the shimmer of Nocturne Bay was visible. But—that vibration her feet had felt was something that didn't belong in this beautiful city. "[cold]I hope it's just my imagination." Caitlyn adjusted the collar of her uniform. White and navy—custom-made Enforcer gear. She wore pants instead of a skirt, the better for running and vaulting over obstacles. Six years since she'd become a peacekeeper. She'd climbed all the way to Chief Investigator on nothing but her marksmanship and her instincts in the field. She wasn't like those pampered rich kids who'd only ever graduated from the academy. "[laughing]You worry too much, Cait." Vi clapped her on the back with a bang. The careless force of it nearly sent Caitlyn stumbling forward. "[angry]Hey, cut that out!" "[laughing]Sorry, sorry." Even as she apologized, Vi was grinning without a trace of remorse. Her strong-willed, steel-gray eyes narrowed mischievously. —Honestly, this partner of hers. Caitlyn let out a sigh. Ahead of them, people who'd come up from Zaun via the elevators walked past. Their clothes were soot-stained, their hands full of tools and bundles of scrap. The undercity of Zaun—where the air was stagnant and always hazy gray with chem-tech smoke. If Piltover was the light, then Zaun was the shadow. And from that shadow, countless people came up every day to work. The Gate Bridge in the border zone was packed at this hour. The great bridge connecting the upper and lower cities. Beyond it lay Mist Alley, where gas lamps flickered. Gray Lantern Lane, lined with food stalls. A gray district where all sorts of characters loitered. As she gazed out at that scenery, Caitlyn found herself thinking. I'm the daughter of the esteemed Kirschtein family. My parents have connections on the Council, and my brother's already a hugely successful merchant. I didn't have to choose a dangerous job like being an Enforcer. But. "(I couldn't just stand by and watch from a safe place.)" When I was sixteen, I saw it from the window of the mansion. A riot breaking out in the border zone. Enforcers desperately trying to protect people. From that day on, I stopped being just a sheltered young lady. I went to the shooting range, pushed my body to its limits, and buried myself in books studying law and science. People laughed and called me "the oddball of the Kirschtein family," but I couldn't have cared less. I want to protect this city with my own hands. The small, crescent-shaped scar on my left temple—that's a medal I earned in my first real fight. When I'm concentrating on a sniper shot, I unconsciously trace it with my finger. And then, just at that moment. "[laughing]Hey, hey, pink-hair! What's an ex-gangster doing around here!" Three kids who looked like they'd come from the border zone surrounded Vi. The smallest boy tugged at the hem of Vi's uniform. "[angry]What'd you say, you brats! Who do you think you're talking to, an ex-gangster like me!" Vi put on a scary face. But the corners of her mouth were twitching. The next instant. "[laughing]Alright, grab on!" She effortlessly lifted the child up and hoisted him onto her shoulders. "[excited]Yay! So high up!" "[laughing]Ahaha, how d'you like that!" Vi started spinning around on the spot. The other kids clamored, "Me too!" "Me next!" Their excited voices echoed across the blue cobblestones. The moment Caitlyn saw that— Thump. Her heart suddenly pounded loud in her chest. "(What is this... what's wrong with me...)" Her heart was racing, and she couldn't breathe properly. Vi's unguarded smile. Those powerful arms holding the child so gently. Those eyes, so warm you'd never believe she was an ex-gangster. "(Why are you pounding on your own like this, my stupid heart!)" Caitlyn clenched her fist tight. At times like this, she never knew what to say. The supposedly perfect Enforcer Caitlyn, her mind going completely blank just because of her partner's smile. "[cold]...We don't have time to play with children, Vi." She somehow managed to open her mouth, but even she could tell her voice sounded terribly distant. With the child still on her shoulders, Vi grinned. "[laughing]What's the matter? Jealous?" "[angry]N-no! I'm not jealous!" Jealous. At that word, her ears flushed burning hot. "[laughing]You want a shoulder ride too, Cait?" "[angry]Don't be ridiculous! Let's go!" I strode off with long steps. Behind me, I heard Vi laugh and say, "Man, you're no fun." No fun is just fine with me. I don't know this feeling, and I can't afford to acknowledge it. They continued their patrol for another hour or so, then stopped at their usual café. A long-established place on Sun Promenade, "La Corantine." Their specialty, the hex-berry tart, was exquisite. The white awning over the terrace seats fluttered gently in the breeze. "[excited]So good! Man, this is just so good!" Vi had already devoured three tarts, her mouth ringed with cream. Her steel-gray eyes were sparkling like a child's. It was utterly uncouth. "[cold]Wipe your mouth. You look disgraceful." I pulled a white handkerchief from my uniform pocket. The embroidered Kirschtein family crest—a winged sword emblem—glinted faintly in the morning sun. "[surprised]Oh, thanks. ...Wait, this is amazing. A noble lady like you carries something like this around?" Vi stared intently at the handkerchief. "(I carry it because I want you to use it, you idiot.)" The me inside my heart screamed. "[cold]It's standard preparedness for an Enforcer." What came out of my mouth was, as always, a curt line. That was the best I could manage. Caitlyn reached for the hex-rifle propped up beside her. Her trusted long-range precision marksman's weapon. Effective range: approximately 800 meters. The blue light of the hex-crystal flickered deep within the barrel. As usual, I checked around the trigger for any dust. This weapon, at least, never betrays me. And then, at that moment— BOOOOM! Far ahead, in the direction of the border zone, an explosion erupted. The shockwave reached them, rattling the café's windowpanes violently. "[scared]Ah!" "[serious]Cait!" Caitlyn was already on her feet. She raised her hex-rifle, glaring in the direction of the blast. "[serious]Let's go, Vi!" The two of them broke into a run simultaneously. The scene was another café, facing a street near the border zone. Its terrace seating was badly wrecked, white tables and chairs scattered in splinters. A large crack ran through the wall. And a pungent, irritating odor hung in the air. "(This smell...!)" Caitlyn swiftly scanned the scene. Amidst the rubble, a distinctive green liquid glistened here and there. "[serious]Zaunite chem-tech... and military-grade refinement at that. This wasn't just an accident." Shimmer. A prohibited chemical substance extracted from veins deep beneath Zaun. I'd seen the data countless times during my training with the forensic analysis unit. This purity, this residue pattern—half-baked skill couldn't produce this. "[serious]Vi, secure the perimeter. There might still be people inside." "[serious]Got it!" That was when it happened. "...Ugh... uuugh..." A faint groan. It came from beneath the collapsing framework of the terrace seating. "[scared]Ms. Noela! The owner!" Vi's body moved before her mind could think. She dove bare-handed into the groaning pile of rubble. It was dangerous. It could collapse again at any moment. But with instincts honed in her Zaun days, she instantly identified the rubble's fulcrum point. "[angry]Get out of the way!" Vi shouldered a steel beam aside. Just like that, she dragged out the old woman in the white apron—Noela. "[gentle]You alright, ma'am!" "...Oh, you... thank you..." Caitlyn watched the exchange, breathless. It was a move no merely well-mannered Enforcer could ever imitate. Rough, violent, but—possessing a will to "protect" stronger than anyone else's. Then, her eyes fell on Vi's right arm. "(She's bleeding...!)" Cut by the rubble, the sleeve of her uniform was stained red. The moment she saw it, Caitlyn's chest tightened sharply. "(Every time you get hurt, my heart aches, you know...)" But there was no way she could say that out loud. I'm a professional Enforcer, the field commander. "[serious]...Vi, make sure you get that wound treated properly later." She barely managed to say that much. Her voice might have trembled, just a little. Then, Caitlyn crouched down at what appeared to be the epicenter of the explosion. She picked up a metal fragment with her fingertips. Warped, but its shape remained. "(...Outdated Zaun-made parts?)" The parts themselves were close to shoddy. But the way they were assembled, and the residue of the chemical substance clinging to them— "(This level of sophistication... it's the work of a pro. A highly skilled one, at that.)" She'd have to send an urgent analysis request to Analyst Haines. But before that, a bad feeling swelled within her. "(Using outdated parts isn't about cost. This is... deliberate. They're leaving a trail on purpose.)" The culprit wants to announce their presence. No declaration, no demands—just as if to terrorize the city. A quiet, insidious threat. She felt a faint throb from the scar on her temple. Evening. Leaving the scene's lockdown to the next shift, the two of them walked back to headquarters. The setting sun streaming in from Nocturne Bay dyed the city of Piltover orange. The white buildings glowed gold—on any other day, it would have been a beautiful sight. "[gentle]Hey, Cait. You had a scarier look on your face than usual today. You okay?" Fussing over the bandage on her arm, Vi peered into her face. She was so close. Her heart started pounding loudly again. "[surprised]...!" I took a step back. "[cold]What about you? Did you get that wound treated properly?" "[laughing]This? It's just a scratch. More importantly..." Vi smiled. In the sunset, her pink hair swayed softly. Her steel-gray eyes looked straight at me and narrowed. "(Could it be that I—)" The turmoil in my chest had reached its limit. The words were right there, on the tip of my tongue. "(About Vi, I—)" "[surprised]...It's nothing!" I dashed up the stairs to headquarters at a quick pace. Behind me, I heard Vi call out, "Hey, what's wrong with you!" but I couldn't turn around. And then, at the Enforcer headquarters that evening. Analyst Haines threw open the door to the analysis room with a frantic look. The usually mild-mannered man in his forties was pale as a sheet. "[scared]Chief Kirschtein...!" "[serious]What is it, Haines?" With trembling hands, Haines held out a data sheet. "[scared]I analyzed the bomb's chemical formula... This pattern matches only one entry in the database." An old research paper appeared on the screen. Dated eight years ago. Submitted by—"Jillian Vero." "[scared]Jillian Vero... a genius chem-tech engineer from Zaun who studied abroad in Piltover eight years ago. However, she disappeared immediately after completing her program. All official records after that have been completely erased by someone." Caitlyn looked at the old photograph displayed on the screen. Short, silver-gray hair. Provocative, amber-colored eyes. A confident smile on her lips. "[scared]Chief... this chemical formula is something only she could create." Something stirred deep in Caitlyn's chest. It wasn't just a professional's