Episode 21 marked the physical and mental break down of Ji An. After the confrontation with Ji Soo who berated her, Ji An felt even more miserable. Realizing nothing can be undone or fixed, Ji An gives up and decides to end everything.
In episode 22 the Seo family as well as Do Kyung continue to worry about Ji An’s disappearance and are searching for her. Do Kyung even gets in touch with Hyuk, because he knows he is befriended with Ji An. Hyuk doesn’t know where Ji An is either. Do Kyung asks Hyuk to call him, when Ji An contacts him without telling Ji An. On a trip to Incheon with Ji Soo on request of her boss the baker, Hyuk recognizes in a glimpse Ji An, when
Ji Soo and he were just on their way back. Hyuk called a cab for Ji Soo and returned to the beach. So he found the missing Ji An!
Credit: KBS World TV@youtube.com, thank you!