Gong Hyo-jin's 'A Bona Fide Killer' Sets Series High as Kingfisher Mystery Deepens

MBC's Friday-night drama "A Bona Fide Killer" cracked double-digit ratings for the first time, powered by new reveals about its two leads. The sixth episode drew a 10.2% nationwide household rating, according to Nielsen Korea, marking a series high.

The episode began peeling back the shared history of Yoo Bo-na, played by Gong Hyo-jin, and Kwon Tae-seong, played by Jung Jun-won. It also sharpened the link between their past and the present-day case driving the show.

Yoo Bo-na, a killer who targets criminals, ran into her husband Kwon Tae-seong at a client meeting. The moment forced her to face a hard truth. Her husband, a reporter chasing the truth behind the same case, could cross her path again on the job. She went home and asked him out on a date.

When she said she just wanted an ordinary day, he answered, "Like the day we first met?" The scene revealed that the two remember their first meeting differently.

In a flashback, a younger Yoo Bo-na, dressed as a Red Devil soccer fan, came down a staircase and found Kwon Tae-seong lying unconscious with blood on his head. He has no memory of it. In other words, the couple had already crossed paths before the first meeting either of them recalls.

The episode also opened a window into Yoo Bo-na's childhood and inner circle. She found a listening device hidden inside a doll sent by her Russian friend Seul-gi. "Pull this again and I'll fry you with a lightning bolt," she warned.

Kwon Tae-seong knows Seul-gi exists but has never seen her face. Yoo Bo-na told Bong Tae-min, played by Kim Nam-hee, that Seul-gi would soon arrive in South Korea. Bong Tae-min made clear he did not want to see her. What happened between Yoo Bo-na, Bong Tae-min and Seul-gi has not been revealed.

An earlier flashback showed a young Yoo Bo-na escaping a burning orphanage while holding someone's hand. That image cut to her present life as a sniper-wielding killer, raising the question of how the fire connects to who she has become.

Kwon Tae-seong's past came into view as well. He received a text from an unknown sender that read, "You're keeping your promise. Good boy," and grew visibly uneasy. He also had a nightmare about being tied up and abducted in a forest.

His link to Kingfisher, the case at the center of the show, remains unresolved. Kwon Tae-seong once nearly died at a Kingfisher shooting scene. He now works as a reporter covering a range of social issues. Why he suddenly walked away from reporting on Kingfisher has not been explained.

The sixth episode also showed detectives Lee Dong-jin, played by Lee Sang-yi, and Beom Seong-hoon, played by Choi Woo-sung, on a stakeout in a car. A news report about Kingfisher's "one shot, two kill" sent them racing to the scene. That moment hit a peak rating of 11.8%.

"Bubbly Killer" is based on the Kakao Webtoon of the same name. The seventh episode airs on the 21st at 9:50 p.m. KST.