[1][2][3] Go Se-yeon (Park Bo-young) is a beautiful prosecution lawyer at the top of her game, and Cha Min (Ahn Hyo-seop) is her friend, an unattractive but rich heir to a cosmetics empire.

The "Abyss" is a celestial object which has the power to revive anything that has died; the reincarnated bodies take on the appearance of that person's soul.

Go Se-yeon takes on a 'plainer' appearance, whilst Cha Min becomes very attractive and young; virtually the opposite of before.

[4] The first script reading took place in February 2019 in Sangam-dong, Seoul, South Korea.

[17] Actors Seo In-guk and Jung So-min, who acted in The Smile Has Left Your Eyes (2018), made a special appearance.