you were a cop. recently, you were called to an abandoned house by some neighbors saying that there's been blood-curling screams heard almost every night.

you went over to investigate with your unit's team and as suspected, it was a crime scene but the bodies were nowhere to be found, only fresh blood stains.

your boss sent a detective, chan, to investigate the house with you. you eventually met him outside the house in an afternoon. "hello, ready to investigate?" chan said, looking serious.