“Full River Red” is the great Chinese director Zhang Yimou’s “hold my beer” movie moment.

A creator of epic-length period pieces, romantic or action sagas in the tradition of David Lean — “Raise the Red Lantern,” “Hero,” and “House of Flying Daggers” — and a big slice of Hollywood period piece cheese (“The Great Wall”), he’s taken to heart the “epic” label slapped on latter Tarantino tales and Rian Johnson’s “Knives Out” comic mystery thrillers.

His “answer” to those films is a two hour and forty minute 12th century double and triple cross tale, bloody-minded political intrigues lampooned in a sort of “Daggers Out” thriller giving a back story to a famous jingoistic poem of the day, well-known in the People’s Republic to this very day — “Full River Red.”

Zhang’s film is patience-testing and dense — a series of schemes, assassinations, summary executions and intrigues surrounding a letter lost when a Jin Dynasty emissary is murdered the night before a big negotiation with the Song. It is excessive, stunningly-detailed from the first, with period-appropriate score and instrumentation decorating the opening scenes.

It is also — pretty much from the opening moments — laugh-out-loud funny. Characters wince and grimace and chuckle at the difficulties, dangers and deadly threats they suffer at each other’s hands. Bodies pile up as throats are slit and we’re reminded of just who invented “water boarding” torture as an interrogation method, and how long it’s been practiced.

But with “vinegar?” That’s seriously messed up.

The stakes rise and the deception — there may be traitors exposed by the contents of that missing letter — deepens. And the score shifts to amusingly anachronistic Chinese rockabilly, pop etc. used as “traveling music” as functionaries and soldiers quick-march or sprint from one end of a large, borderlands Song Dynasty complex to the other.

In the hours before dawn, that emissary’s body is found. A lot of guards had to be slacking off, or in on it, for that to happen. Deputy Commander Sun Jun (Jackson Yee) rounds them up, makes them draw straws and commences with the throat slashing.

A lowly corporal, Zhang Da (Shen Teng) scrambles to fake, cheat and talk his way out of the summary executions. Lucky for him he can lie-on-the-fly. Dragged in front of the tubercular prime minister (Lei Jiayin), he correctly guesses that this might have been over a missing message. He, of all people, is given “two hours” to investigate the treachery and find that letter.

Commander Sun is to keep an eye on his progress. Sadistic Lord He (Zhang Yi) and officious Lord Wu (Yue Yenpeng) are to keep an eye on Sun.

Everyone either knows more than they’re letting on, or less, including the dancer (Wang Jiayi) who entertained that ambassador and might have been the last to see him alive.

All Zhang Da needs to know is that he’s got two hours to figure this out, and figure out a way to survive uncovering what he finds out. Because everybody he deals with has a murderous agenda, even if a lot of them — Sun is his “uncle” — are related, have known him and are likewise known to him.

He keeps asking Lord Wu if “I can use your background.” The son of an imperial concubine, Wu’s connections to the emperor are less noble. He’s basically a titled “nepo baby.” And he’s touchy about that.

Slice-happy Sun keeps killing suspects and witnesses, something everybody openly suspects is merely a murderous means of covering his tracks.

“A wolf or a dog,” he philosophizes at one point (in Mandarin with English subtitles), “depends on what you feed it.”

But whodunnit? And where is that accursed letter?

It used to be common practice to try and read subtexts and non-communist-approved messaging into Zhang’s early films — “Red Sorghum,” “Ju Dou” and “Raise the Red Lantern.” But you don’t have the prolific career he’s had by not toeing the party line, or never crossing it.

Like such WWII films as “The Flowers of War” and “Cliff Walkers,” “Full River Red” plays as straight-up Chinese nationalism, building a tale around a patriotic poem about “revenge” against one’s enemies and re-taking “our land.”

But there are sly digs at heartless, faithless bureaucracy, arbitrary punishments and government by connections and personal decree.

My favorite scene here is basically a game of “rock paper scissors” involving Imperial warrants, seals, decrees and licenses, with everyone sure he is untouchable by the others because he possesses one of those, and all are comically-confused about what edict trumps which decree.

For all the complications, it’s pretty obvious that the sheer scale of the film is what accounts for its repetitive, talky and occasionally tedious running time. Hundreds of armor-plated extras, a large complex with assorted courtyards and barracks, messages being marched or run hither and yon, every double-cross uncovering a new alliance or allegiance, another twist in the plot.

But longtime fans of one of China’s greatest living filmmakers won’t want to miss this one. It isn’t every day that Zhang Yimou jokes around. You’ll want to be there for every bloody punchline.

Rating: unrated, violence

Cast: Shen Teng, Jackson Yee, Zhang Yi, Lei Jiayin and Wang Jiayi

Credits: Directed by Zhang Yimou, scripted by Chen Yu and Zhang Yimou. An Edko release.

Running time: 2:39