When 28-year-old Seo-yeon gets a call from a woman named Young-sook asking for her friend. Seo-yeon hangs up thinking the woman has the wrong number, but later learns that the call was coming from the same house 20 years ago.
Because it is populated by TOP 10 ranking since 2020, it is still a work in progress. Multiple links in the same country lead to different streaming versions.