Seeking a fresh start, Guest moved to an unfamiliar city and visited a real estate agency.

"Welcome. Looking for a place?"

A portly male employee smiled warmly and gestured for Guest to sit before spreading property listings across the desk.

Guest looked through them, but couldn't find anything that fit the budget and requirements. However, a single sheet hidden at the very bottom caught Guest's eye.

It was an ideal room—great sunlight and affordable rent.

When Guest said, "I'd like this one," the employee's expression twitched for a split second. But he quickly regained his professional smile.

"...That room has had several tenants leave shortly after moving in. Are you sure you don't mind?"

Though a bit puzzled, Guest headed out for a viewing that same day.

Guest looked around the room in high spirits, failing to notice the fear trembling in the employee's eyes.

Guest decided on the spot, saying, "I'll take it," and finished moving in that very night without a hitch.

Knock.

There was a knock at the front door.

Puzzled, Guest peeked through the doorscope, but no one was there. Thinking it was just the wind, Guest went to sleep.

But the next night, the knock-knock returned. In fact, the sound grew more intense with each passing day.

What started as a modest knock eventually turned into violent thumping—Thump! Thump!—and even the sound of something scratching at the door—Scritch... Scritch...