Viewers disappointed by the spin-off of the 2009 spy-thriller hit “IRIS,” might not have much riding on the sequel to the pioneer action original, but the tight, well-edited highlights reel that ran at the “IRIS II” press conference in Seoul on Thursday promises a seat-gripping, intense, muscular and slick series.

The action is definitely bigger. Explosions singe the screen. Fight scenes are gritty, tough and well choreographed, with no excess flourishes. The cinematography is silver screen-grade, all the more heightened by overseas locales like Hungary, Cambodia, Japan and the endless window-smashing, helicopter-leaping, kick-ass hand-to-hand combat stunts that squeeze out any room for boredom.

Sure, there is definitely a fair share of melodramatic romance in the mix, with leads Jang Hyuk and Lee Da-hey kissing on a bridge at night and frolicking in the snow, and, if the plot plays out as planned, with B2ST’s Yoon Du-jun’s also vying for the affections of Lee’s heroine, NSS agent Ji Soo-yeon.

Throughout the sneak preview, action veteran Jang Hyuk held up his end of the bargain with no-frills, all-out stunts.

Jang’s “The Slave Hunters” co-star and “IRIS II” heroine Lee Da-hey proved she is game for action as well with strong moves and aerial jumps.

At the press event, Lee revealed the hardships of prepping for all those stunts, saying, “We were practicing at action school together and then I noticed that Jang Hyuk had a lot of blood, right there on his forehead, but he just wiped it off like it was nothing, I guess because he has done so much martial arts and action himself.” 

“Every moment is hit-and-miss,” said Jang. “I always am alert when filming.”

“There were many dangerous scenes in as much as the scale of the sequel is more grandiose,” said Jang, recalling a particularly nerve-racking moment. “When filming a scene where I roll over a car, at one time my leg got caught in the car and I found myself being dragged by it. That moment was a bit risky, but thankfully we got it in the second take.”

Now, a good series cannot float without a strong plot, and it is in this area where “IRIS II” might fail to live up to viewers’ expectations.

The sequel opens three years after the as-of-yet unsolved demise of the first installment’s hero, NSS agent Kim Hyun-jun (Lee Byung-hun).

NSS Task Force A Team Head Jung Yoo-geon (Jang Hyuk) and his team are busy trying to unveil the true identity behind the secret organization IRIS while also acting as bodyguards at a South and North Korea summit. Operative Jung (Jang Hyuk) must also transport a rogue NSS director to safety, but is ambushed by IRIS and mysteriously disappears.

The sudden return of Jung, presumed dead-in-action, promises to add fuel to the plot. It is when Jung reappears that fellow NSS agent Lee Ji-yeon (Lee Da-hey) discovers that Jung’s disappearance is all part of a large-scale conspiracy.

While the story might come across as a little bit been there, done that (especially since “IRIS” lead Lee Byung-hun’s hero also pulled a disappearing act in the original), it is hard to tell without seeing the series just how many similarities there will be between the upcoming sequel and “IRIS,” and its spin-off “ATHENA: Goddess of War.”

Should the plot play out in all too familiar fashion, ratings might taper off as the drama progresses.

That is precisely the scenario that Chung Tae-won, producer at the drama’s production company Taewon Entertainment, wishes to avoid.

After “IRIS” made it big on the small screen in 2009, “we did a spin-off ‘ATHENA,’” said Chung. “At first the response was explosive, but as the episodes aired, viewer ratings declined. We are trying not to repeat the same mistakes this time around.”

Chung revealed that he and the team are continually reviewing the script, looking to see if anything is missing, and if there is anything to fill in those gaps.

“We are into filming our 12th episode, but we are still doing extra filming for episodes one and two.”

Chung also promised that “IRIS II” would be “more realistic” than its predecessors.

“IRIS II” starts airing Feb. 13 on Wednesdays and Thursdays at 10 p.m. on KBS 2 TV. Jang Hyuk, Lee Da-hey, Lee Bum-soo, MBLAQ’s Lee Joon, B2ST’s Yoon Du-jun will be starring in the series.

By Jean Oh (oh_jean@heraldcorp.com)