[7] Based on the Kakao Webtoon webtoon Amazing Rumor by Jang Yi, it centers on the titular character So Mun, a high school student with a disability who is enlisted to be part of the Counters, a group of paranormal hunters who search for and fight against evil spirits that escape from the afterlife to prey on humans.

[16] In the fictional city of Jungjin, a group of four demon-hunters called the Counters bear the arduous task of searching for and banishing evil spirits (akgwi)[b] that escaped the afterlife to gain immortality.

The Counters were once in comas when a partner spirit from Yung, the boundary between the afterlife and the world of the living, possesses them and gives them perfectly healthy bodies and consciousness along with superhuman strength and supernatural abilities.

[54] Through OCN and tvN, a special broadcast titled The Uncanny Return (경이로운 귀환) aired on February 7, 2021, at 22:40 (KST).

[55] The special broadcast stars Jo Byeong-kyu, Yoo Jun-sang, Kim Se-jeong, Yeom Hye-ran, Ahn Suk-hwan, Choi Kwang-il, Ok Ja-yeon, Lee Hong-nae and Jung Won-chang.

[56] In July 2020, Jo Byeong-kyu, Yoo Jun-sang, Kim Se-jeong and Yeom Hye-ran were confirmed to star in the series.