The floorboards in the hallway groaned again, closer this time. The shadow of In-ah’s footsteps stopped right outside the bedroom door.

Inside, the air turned ice-cold. So-min, Da-eun, and Rora scrambled in absolute silence. With no time to dive back under the bed, So-min slipped flat against the wall behind the open door, pressing herself into the narrow gap as the handle clicked and swung inward.

In-ah stood in the doorway, her arms crossed, her eyes scanning the room. She looked at Da-eun and Rora, who were standing awkwardly by the window, trying to look natural.

"I'm heading out to check the perimeter lines before it gets completely dark," In-ah said, her voice tight and clipped. "I expect both of you to stay inside. No wandering into the woods. Do you understand?"

"We understand," Da-eun said quickly, nodding.

In-ah lingered for a second longer, her sharp gaze sweeping the corners of the room before she finally turned on her heel and walked away. A few moments later, the heavy front door of the cabin clicked shut, and the sound of her boots faded down the porch steps.

The second she was gone, So-min stepped out from behind the door, her face pale. She checked her phone, her thumb hovering over a string of frantic, unread text notifications from Hobi.

"I have to go back," So-min whispered, her voice trembling but resolute. "Hobi’s already tracking my location status. If Do-hyun gets back to the city house and finds out I escaped through the basement window, he’s going to lock down everything completely. I won't be able to help you guys from the inside anymore."

"But it's getting dark out there," Rora said, grabbing her arm. "And that masked person is still in the woods."

"I'll take the lower valley road, away from the water tower," So-min insisted, pulling her jacket tight. "They were waiting for you guys at the shed, not the main road. If I leave now, I can catch the last bus back to the city before anyone realizes I was gone."

Da-eun walked her to the back door, her heart heavy with anxiety. "Be careful, So-min. Keep the childhood cipher open on your phone. The second we figure out what those initials mean, we’ll send it through."

With a quick, tight nod, So-min slipped out into the gathering twilight, her figure rapidly disappearing into the shadows of the valley trees. Da-eun locked the door behind her, turning back to face Rora in the darkening cabin.

They were back to where they started—isolated, terrified, and staring at a code they couldn't break.

The sound of In-ah’s boots stomping onto the front porch forced Da-eun and Rora to scramble away from the back door. They threw themselves onto the living room sofa just as the front door swung open, letting in a swirl of freezing night air.

In-ah stood in the entryway, her face pale and her breathing shallow. She didn't look at the girls; she simply locked the door with three separate turns of the key and pulled the heavy curtains shut. "We aren't leaving this house tonight," she said coldly, her voice shaking slightly. "The perimeter isn't safe."

For the rest of the evening, a suffocating silence hung over the cabin. Locked in their bedroom, Da-eun and Rora abandoned the mystery of the initials J.Y. and Y.E. for the moment. Instead, they spread out the old documents they had taken from the city, looking for anything that explained the sheer scale of the alliance.

As Rora lined up the financial ledgers next to the family crests, she noticed a bizarre pattern in the properties owned by the four families.

"Da-eun, look at this," Rora whispered, pointing a trembling finger at an old architectural blueprint of the Kim family's main estate in the city. "The core ownership of all four families' assets isn't tied to a bank. It's legally anchored to a specific piece of land."

Da-eun leaned in, her eyes widening. "The old courtyard behind the Kim mansion..."

"Exactly," Rora said, her voice dropping lower. "The path to whatever breaks this entire pact isn't out here in the countryside. The countryside was just a distraction to keep us away from the city. The real entrance—the physical path that holds the truth of how our families are bound together—is hidden right beneath the old courtyard back home."

Before the weight of the discovery could fully sink in, the window pane right behind them shattered.

A heavy rock tore through the glass, sending sharp shards raining down onto the floorboards. Through the broken window, a dark, masked figure lunged forward, clawing at the curtains to get inside the room.

"Get back!" Da-eun screamed, grabbing the heavy wooden desk chair and throwing it forward to block the window frame.

Rora scrambled backward, screaming for In-ah. The attacker thrust a gloved hand through the broken glass, trying to grab the manila folder from the bed, but the chair slammed against their arm with a sickening thud.

In-ah burst into the room, a heavy iron poker in her hands, her eyes wild with fury. Seeing a weapon, the attacker swore under their breath, pulled back through the shattered window, and vanished instantly into the pitch-black woods.

The terror of the second attack broke the girls completely. The reality of how exposed they were in the isolated cabin finally crushed their resolve. They couldn't run, they couldn't investigate, and they couldn't fight.

The next morning, under In-ah's strict, silent surveillance, they packed their bags and were driven back to the city. The sheer trauma of the encounter forced the trio—Da-eun, Rora, and the safely returned So-min—to retreat into total isolation.