“I, the Executioner” actors Jung Hae-in (left) and Hwang Jung-min pose for a photo during a press conference in Seoul on Tuesday. (Yonhap)

Ryoo Seung-wan, who directed the 2015 action blockbuster “Veteran,” is returning with sequel “I, the Executioner” this fall.

The movie picks up the story of veteran detective Seo Do-chul (Hwang Jung-min) nine years after the first installment, as he is joined by rookie detective Park Sun-woo (Jung Hae-in), who is full of passion and a sense of justice.

Do-chul and Sun-woo investigate a high-profile murder case of a professor which seems to be in line with the previous murders, as a serial killer publicly uploads a video in which he has designated the next victim.

Scene from “I, the Executioner” (CJENM)

Hwang Jung-min (left) plays veteran detective Seo Do-chul and Jung Hae-in (right) plays rookie police officer Park Sun-woo in “I, the Executioner.” (CJENM)

Jung Hae-in, who starred in Hwang’s latest historical hit flick, “12.12: The Day,” but never shared a scene with the veteran actor, said he joined “I, the Executioner” without knowing what it was.

“I received an offer from Ryoo, with him just explaining to me that we’d do a fun project together. But then, after I heard that it would be this movie, I was overwhelmed with joy, felt my heart flutter and even became impassioned," Jung said.

Ryoo pointed out that Jung’s versatile acting in previous projects allowed him to cast Jung to add something fresh to the movie.

Hwang said that adding Jung created an unprecedented energy.

“Some of the scenes where we meet are just hilarious. Jung’s joining our series has made a new kind of energy,” said Hwang, adding that the action sequences are more detailed compared to the previous installment.

“I had to rely on Hwang during the shooting. I learned a lot going through rounds of detailed rehearsals,” Jung said.

The movie, also referred to as “Veteran 2” here, is a sequel to 2015 blockbuster “Veteran,” which attracted 13.41 million moviegoers.

“To be honest, I didn’t think ‘Veteran’ would be such a hit. It was not a big-budget movie, something of a family movie. But because I loved all the characters and it was a pleasurable production experience, I wanted to make a sequel. I didn't mean to take this long, however,” said Ryoo.

The movie, even before its opening, has garnered nationwide attention for being the only Korean film that was invited to the official section of this year's Cannes Film Festival.

“I, the Executioner” was listed in the midnight screening category, which is a non-competition section dedicated to introducing films in genres like action, fantasy, horror, thriller and noir.

The movie was also invited to the 49th Toronto International Film Festival.

“I, the Executioner” hits local theaters on Sept. 13.

From left: “I, the Executioner” actors Jung Hae-in, director Ryoo Seung-wan and Hwang Jung-min pose for a photo during a press conference in Seoul on Tuesday. (Yonhap)