I think that Dr.heo already tried setting hana free but he got caught and they took hana back making hana more miserable,so he thought that it'll be better for hana to die than suffer being their "lab rat".
I think that Dr.heo already tried setting hana free but he got caught and they took hana back making hana more miserable,so he thought that it'll be better for hana to die than suffer being their "lab rat".