A baby box is a small space, where parents can leave behind their babies anonymously. Sang Hyun finds new parents for a baby left in a baby box and makes a special deal with them. He calls himself a broker of good will. Sang Hyun works with Dong Soo in this endeavor. They get involved with So Young, who placed her baby in the baby box, but has now come back for her baby. Meanwhile, Detective Soo Jin and Detective Lee chase after Sang Hyun and Dong Soo.
