Recording engineer Seong-hyeon is troubled by a request for post-production dubbing. The leading actress, Mi-jeong, has passed away, and no one knows the content of the ad-libs she performed in a crucial scene of the film. Minor actress Min-young visits Seong-hyeon’s studio to record Mi-jeong’s lines, but the director who was supposed to come is nowhere to be found. Humming stimulates a sense of mystery and imagination against the backdrop of a secluded hill and a shabby recording studio. The film intertwines conversations between Seong-hyeon and Min-young, Seong-hyeon’s memories of the deceased Mi-jeong, and scenes from the film Seong-hyeon and Mi-jeong worked on together, placing itself at an angle between reality and cinema, life and death. It unfolds like a languid and bizarre midday farce or a chilling and sorrowful ghost story, gently touching upon the secretive and significant moments of the world.