The penthouse at the top of the Han River tower was always too quiet when Kim Jisoo was alone in it, which was most of the time, and entirely too loud the second Kim Jennie crossed the threshold.
At twenty-seven, Jisoo was the youngest chief executive officer in the history of her firm, a woman whose name made boardrooms quiet and whose signature could shift market indices by fractions of a percent. She wore slate-gray tailored suits that looked like armor, kept her hair in a severe, low knot, and lived on black coffee, cold precision, and the terrifying weight of a multi-billion-dollar corporate empire she had inherited before she was legally old enough to drink champagne in most foreign capitals.
Yet, to Jennie—who had just turned twenty-two and smelled persistently of jasmine tea and crushed vanilla bean—Jisoo was simply the person who kept the light on in the hallway.
They had known each other since the cradle, or rather, since Jisoo was five years old and stood over Jennie's crib with the grim, unyielding solemnity of a tiny general inspecting a newly acquired territory. Their families had been intertwined by old blood and older money—the Kim and Kim alliances that sounded like a bad joke at cocktail parties but felt like iron rails in reality. When Jennie was four, Jisoo had once bitten a neighborhood boy who tried to snatch her ice cream cone, earning herself a week of grounding and a permanent, fierce sense of ownership over the small, round-faced toddler who followed her everywhere like a duckling with expensive hair bows.
There had never been a moment in Jisoo's life where Jennie wasn't there. When Jisoo pulled all-nighters for her undergraduate finals at Seoul National, twelve-year-old Jennie would curl up on the rug of her study like a small, sleepy cat, breathing in rhythm with the scratching of Jisoo's pen until she dozed off. When Jisoo took her first major loss in corporate restructuring at twenty-four, it was Jennie—then nineteen and wearing an oversized university hoodie—who had quietly appeared at her office door with a greasy bag of tteokbokki and a stern command to stop staring at the wall.
Jisoo's love for her had always been absolute, monumental, and entirely unmapped by the laws of ordinary affection. It was the love of a fiercely protective older sister who would have cheerfully set fire to Seoul if anyone dared to look at Jennie sideways. If Jennie said she liked the tartness of a specific strawberry from a farm in Gyeongju, Jisoo had crates of them delivered by morning courier. If Jennie mentioned offhand that she wished she could see the northern lights without the freezing cold of a commercial tour, Jisoo had spent forty-eight hours on the phone with aviation brokers until she secured a private charter with a heated glass observation dome.
She shouldn't have done it. She knew she shouldn't have. Every time Jisoo indulged Jennie's whims with the terrifying, bottomless resources of her bank accounts, her internal auditor—the same cold, corporate voice that saved her company millions—whispered that she was creating a monster of dependency. But Jisoo didn't care. The sound of Jennie's laughter, sharp and bright and completely unfiltered around her, was the only currency that mattered.
The golden rule of their dynamic, however, had always been absolute: Jisoo only listens to Jennie.
If Jennie said no, Jisoo dropped matters instantly, regardless of contracts or leverage. If Jennie wanted to walk through the crowded night markets of Myeongdong without bodyguards, Jisoo dismissed her security detail with a wave of her hand, shadowing her from three paces back like a lethal, bespoke ghost. And when Jennie, at eighteen, had complained that the private university chauffeur felt like a babysitter, Jisoo had quietly purchased a controlling stake in the local coffee shop near Jennie's campus just so Jennie would have a place to sit that Jisoo had personally vetted for safety and quiet.
When Jennie turned twenty-one, the world tilted on its axis.
It had happened on a rainy Tuesday night in November. Jisoo was still at her glass-walled desk on the forty-fifth floor, knee-deep in a merger agreement that smelled of printer toner and desperation, when her private elevator chimed. That chime was coded; only three people had the frequency. Her chief of staff, her mother, and Jennie.
