In the 18th episode of “The Legend of the Blue Sea” broadcast Wednesday, things took a turn following the death of main character Heo Jun-jae’s father.

The father was a wealthy corporate chairman who divorced a devoted wife and remarried a deceptive woman. He was secretly given a toxic substance by the latter, which first made him go blind and later led to his death.

Distraught after losing his father, Heo vows to uncover his stepmother and stepbrother’s evil plans to get their hands on inheritance money.

(SBS)

His stepbrother, Chi-hyun, attempts to murder him by paying off Heo’s friend Nam-doo, a known fraudster.

The two hatch a plan to kill Heo with the same toxic substance used on his deceased father, but in a surprise twist it turns out Nam-doo was only acting like a heartless traitor in front of Chi-hyun. In reality he was sharing every detail with Heo.

Meanwhile, the show’s female lead character Cheong (Jun Ji-hyun) finds out how the stepmother had been slowly killing Heo’s father.

Cheong, who is actually a mermaid, has the special ability to read other peoples’ minds when she comes into physical contact with them. She accidentally reads the mind of Heo’s stepmother and instantly sees where all the crime evidence is located.

She helps the police arrest the evil woman. With his plans falling to pieces, Chi-hyun takes out a weapon he was hiding and takes aim at Heo, but Cheong shields him from the bullet.

The story continues in episode 19, which will be broadcast Thursday night on channel SBS at 10 p.m.

“The Legend of the Blue Sea” airs every Wednesday and Thursday. The 20-episode show will come to a close next week.

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