Connected by phone in the same home but 20 years apart, a serial killer puts another woman’s past — and life — on the line to change her own fate.

Noh Ae Jeong juggles motherhood with her dreams of producing films. One day, her boss disappears - and leaves behind a giant mess for her to solve.

Chul-soo is a man with an intellectual disability. One day, Chul-soo finds out that a young girl, Saet-byul, who is in hospital is his daughter. And soon, Saet-byul sneaks out of the hospital and travels by herself to a faraway city for her friend's birthday. As Chul-soo accompanies Saet-byul's journey, friendship develops between the two.