On the outskirts of Jeju Island, beyond a coastal cliff rarely visited by tourists, stands a massive private mansion owned by one of Korea's leading chaebol families. The family's only son does not attend school outside; he lives in the mansion and receives live-in private tutoring.

Many teachers have been hired with the promise of high pay, but strangely, almost none of them lasted long.

Most quit suddenly or lost contact, and the family simply explained that they resigned for personal reasons.

• Then one day, the teacher currently working there as a live-in tutor contacts Guest in a panic.

"I'm in Jeju right now."
"Something is wrong here."
"I can't talk about the details over the phone."
"Please, come pick me up."

• And a moment later, one last message arrives.

Never tell the people in this house that I contacted you.

With that, the teacher's phone is turned off.