Come and Hug Me Temporada 1 Episódio 13

Do Jin finds out that a bloody hammer was delivered to Jae Yi as well as a card written to Jae Yis real name, Nak Won. He asks Senior Inspector Ko to hand over this case to him, stating that these are signals targeted to the case 12 years ago. Despite the senior Inspectors plea not to get involved, Do Jin takes on the case.