Park Hanyul, initially punished with a curfew for a minor infraction, showcases his ability to manipulate plants for water purification. The higher-ups, aware of his potential, lift his curfew and attempt to recruit him to deal with a monster in the Han River. Hanyul, realizing the seniors neglected this issue, agrees to help and asks for his sword back, showing a knack for sensing his surroundings. He then begins using water hyacinths, plants he used to grow, to purify the river, indicating his plan is in motion.