“Byzantine” is the word we use to describe insanely-complicated and sometimes murderously murky political situations. But the literal back-stabbers of the Eastern Roman Empire had nothing on the mess that was Korean politics during South Korea’s dictatorships, coups and assassinations era, the late 1970s and early ’80s.

“Squid Games” star Lee Jung-jae has conjured up a seriously over-the-top, byzantine, violent and fictional thriller inspired by those wild and bloody times. He wrote, directed and stars in “Hunt,” a chaotic and engrossing mystery built around that evergreen of the espionage and political intrigue genre, the hunt for a “mole” in Korean intelligence agencies.

Notice I used the plural there. God knows how many entities and their legions of field agents cross paths and cross swords (not literally) in this veritable civil war among competing agendas between rivals with competing suspicions.

Lee stars as Park Pyong-ho, a top level agent with the KCIA when we meet him. It’s not until he’s present at an attempted assassination of his country’s increasingly dictatorial and murderously repressive president during a visit to Washington that he crosses paths with his domestic security counterpart, Major Kim (Jung Woo-sung).

That attempted-hit on the president and assorted other operations that are lethally compromised tell both men, and their higher-ups, that this “mole” they’ve been wondering about is real. They cannot accept this or that fall guy that the thoroughly corrupt government, whose corruption leaks into every agency in it, puts forth.

As each plunges into the arrests, brutal interrogations and spy games with North Korean agents and defectors to find and catch the spy in their ranks, each has plenty of good, solid reasons to suspect the other of being the mole, or helping cover that mole’s activities.

Lee scripts and stages epic shootouts and attempted hits in D.C., Seoul and Tokyo as each agent, moving further up the ladder, engages in tit-for-tat reprisals and provocations in their game of “Tinker Tailor Soldier Spy” with each other.

Lee makes Park the hotter of these two hotheads, the one that bellows the most credible threats and the quickest to resort to violence. But Park is troubled by what all this means to the safety and stability of his country even as he ruthlessly orders this or personally carries out that. Jung plays the more guarded and in some ways, the more frightening character, the one who won’t hesitate to do what he thinks needs to be done.

Go Yoon-Jung plays a college girl caught up in campus protests against the fascist regime, a young woman Park keeps getting out of jail. “Honey trap,” the other spies wonder. And “He’s not my father,” she explains. Another mystery to puzzle out.

One thing I’m often struck by in Korean action cinema is the sheer human scale of the productions. It’s not just the zombie movies that are filled with teeming masses. Lee treats us to huge, crowded protests broken up by legions of savagely motivated riot police, competing armies of agents trying to shove past each other to access this official or that wounded agent with secrets they need, fighting to get into his hospital room.

Chaos and mayhem are all around as the manipulative U.S. CIA section chief (Paul Battle) emphasizes that America’s limited concerns are “stability,” and no so much how South Korea achieves it.

One of Park’s field recruits tells him a joke (in Korean, with English subtitles). What do you call war in space?

“Star Wars.”

What do you call a war that never quite turns hot?

“Cold War.”

And what’s the name for a war without end?

“Korean War!”

It’s so — here’s that word — “Byzantine” that “Hunt” can be a tad hard to follow. But even that adds to its immersive qualities. Hand-held cameras plunging into brawls, tear gas, chasing assassins and North Korean spies from dead drops to booby-trapped hideaways, the viewer is overwhelmed much the way ordinary Koreans must have been back then and to some degree, even now, with an armed if starving neighbor to their north bent on their destruction.

But that’s what life amid Byzantine intrigues is like.

Rating: unrated, graphic violence and lots of it

Cast: Lee Jung-jae, Jung Woo-sung, Jeon Hye-jin and Go Yoon-Jung

Credits: Scripted and directed by Lee Jung-jae. A Magnolia release.

Running time: 2:06