Do-jin reached the Mapo Bridge late into the night, where a thick fog swallowed the dim yellow streetlights. His left eye was still plagued by that white static, throwing off his balance as he walked alongside the cold iron railing.
He pulled the radio from his bag. The device was trembling now, with a rhythm that sounded like a low moan. Do-jin wasn't looking for physical evidence; the police had already swept the area clean. He was looking for the "Hot Spot"—the exact point where Soo-ah's soul had been violently severed from her body.
At the fourth pillar of the bridge, the radio emitted a metallic shriek that tore through the silence of the night. Do-jin stopped and placed his hand on the railing. Suddenly, his right eye (the healthy one) began to water profusely, while his left eye (the afflicted one) began to display overlapping visions.
He saw Soo-ah, not as a corpse, but as a flickering phantom of light. She was standing there, pleading with someone. Behind her, there wasn't just a man—there was a "Rift" in the air, as if reality itself had been torn open to allow a massive, pale hand, covered in black ash, to push her.
"It wasn't human... Do-jin... it's The Hunter..." The voice came from the radio, but this time it was calmer, like a whisper directly into his mind.
While Do-jin was submerged in the vision, he didn't notice the shadow manifesting behind him. It wasn't Detective Han, but something smaller and more agile. A girl dressed entirely in black, holding a device in her hand that looked like a "Signal Catcher."
"You're far too late," the girl said, her voice sharp. "They swept the frequencies here an hour ago. What you hold in your hand... is the only device capable of recovering what was erased."
Do-jin spun around quickly, scalpel in hand. "Who are you? And how do you know about the radio?"
The girl smiled bitterly and brushed back her hair to reveal a strange medical earpiece embedded in her ear, emitting a faint blue light. "I'm Yuna... Soo-ah's sister. And I'm the reason she was killed. She was trying to deliver the 'Zero Frequency' to me, but 'The Hunter' got to her first."
Before Do-jin could ask more, the ground shook beneath their feet. The radio in his hand began to emit a sound like a muffled chuckle. Do-jin looked at the river below the bridge, only to see dozens of phantom bodies—the frequencies of those who had committed suicide there before—floating above the water, their eyes all fixed on the pillar where they stood.
"We have to leave now," Yuna said, grabbing Do-jin by his coat. "They sensed the device activation. They don't want the truth... they want the 'Engine' that drives the truth. They want your father's radio."
"My father's radio?" The sentence echoed in Do-jin's mind like a lightning bolt. Was his father part of this hell? Was his death years ago just another manipulated "frequency"?
A bullet rang out from an unknown location, shattering the glass of a nearby abandoned car. The great hunt had begun. Do-jin was no longer just a morgue guard; he had become the "Key" that every dark force in the city sought to possess.