Actor Jo Jung-suk made a cameo appearance as a merman in the seventh episode of “The Legend of the Blue Sea,” Wednesday.

Jo, dressed in a 911 rescue officer’s fluorescent orange suit, stops Shim Cheong (Jun Ji-hyun) as she is about to jump in to the Han River.

He thinks Cheong is attempting a suicide, but Cheong, being really a mermaid, is merely trying to catch fishes to quell her hunger.

When Jo and Cheong stare in to each other’s eyes, they instantly recognize that they are of the same kind.

Jo invites Cheong back to his 911 rescue center, where he teaches her the two most important things she needs to know about being in the human world.

(SBS)

Since leaving the water, Cheong had always been penniless and famished.

Jo shows her that the mermaids’ tears, the pearls, have monetary value in human society.

He also tells her that her heart will turn into stone and she will die if Heo Joon-jae (Lee Min-ho) does not love her back.

The next scenes show Jo and Cheong watching a soap opera together and crying buckets of tears into black plastic bags. With the pearls they fetch, the two go on a shopping spree -- the viewers can be assured that for the rest of the show, Cheong will don the most fashionable outfits.

Jo then sees Cheong off home to Heo Joon-jae where he attempts a jealousy tactic. Heo becomes even more protective of Cheong after seeing her with Jo.

Apart from the cameo, Jo most recently starred in the film “My Annoying Brother” as the older brother of EXO‘s D.O.

Park Shin-hye, who also stars in the film as D.O.’s judo coach, said at the movie’s press conference that she wants to play a romantic role with Jo in the future.

By Lim Jeong-yeo (kaylalim@heraldcorp.com)

Related article: Park Shin-hye, D.O. and Jo Jung-suk feature in fashion mag.