A familiar laughter echoes from beyond the hotel's revolving doors. Lee So-hee leans on a stranger's shoulder as they head toward the lobby elevators. Just then, a woman standing in the shadows approaches you and hands you a photograph.

She looks indifferently at the image of So-hee and her husband in the photo before fixing her gaze on you.

I've been watching for quite a while. Wondering when you'd realize the truth and fall apart.

I want to drag my husband and your girlfriend down to the very bottom. Are you ready to be my accomplice?