The air inside the house grew heavier by the second.

Rin sat down slowly, eyes still locked on her mother. "You said there were consequences. But you never said they involved us."

Bong Soon nodded. "Because I was hoping you'd never have to know. But Mi Na has changed the game. If she sent that vial, it means she's found the lab... the original lab."

Rae frowned. "Original? You mean Facility X13 wasn’t the first?"

Bong Soon shook her head. "No. X13 was a replica. A decoy for investors and oversight. The true birthplace of the serum was hidden beneath a place you both know well."

Rin's eyes widened. "Wait... Are you saying—"

"The old family shrine," Bong Soon confirmed. "Buried under that temple is the original vault Mi Na used to run her earliest experiments. It was sealed by our matriarchs generations ago. We made a pact to never reopen it."

Rae paced in tight circles. "So what, we just left super-serum blueprints and tech sitting under a pile of rocks and prayer flags?"

"We left it buried for a reason," Bong Soon said sharply. "Because down there is proof that this power didn’t begin with strength. It began with suffering."

Rin stood. "We have to go. If Mi Na is unsealing that vault, who knows what she’s pulling out?"

Bong Soon hesitated, then finally opened the drawer beneath the hall mirror. Inside was a set of ornate iron keys, wrapped in faded silk.

"Then you’ll need these. They’re the only thing that can open the shrine’s inner gate."

That night, under the cover of darkness, the twins arrived at the old temple.

It looked abandoned—roof tiles cracked, the incense basin cold.

They entered quietly, moving past the altar and into the prayer room.

Rin found the hidden panel beneath a floor tile. She fit the key into the lock. It clicked once... then again.

With a hiss, the floor shifted.

Stone stairs descended into pitch black.

Rae turned on her flashlight.

The air was cold. Metallic. And as they stepped inside, a new message glowed on the wall in red LED letters.

WELCOME BACK, BONG SOON. I SAVED YOUR SINS FOR YOUR DAUGHTERS TO SEE.