In medieval Korea during the Joseon dynasty, the king has fallen ill with what officials maintain is smallpox. This provides a prime opportunity to seize power for Lord Cho (Ryu Seung-ryong), chief state councilor and ruler of the dominant Haewon Cho Clan, whose daughter is the pregnant queen. To solidify their standing, Lord Cho and the queen spread the lie that the king’s son, Crown Prince Lee Chang (Ju Ji-hoon), is a traitor plotting alongside the region’s Confucian scholars to murder the king and claim the throne for himself, thus forcing Lee and his trusty guard to flee for the countryside. All the while, Lord Cho keeps His Majesty sequestered away in his palace, hidden from public view, the better to govern as he pleases until the queen can give birth to a true heir—at which point, the king will be wholly expendable.

It’s a tale of court intrigue and conspiracy, rife with malevolent deceptions and scheming. And that’s not even taking into account the scenario’s most pressing complication: the king doesn’t have smallpox but, instead, is a flesh-eating zombie.

Lacing historical drama with undead terror, Kingdom is a six-episode South Korean series premiering exclusively on Netflix Jan. 25. The finest zombie effort since South Korean helmer Yeon Sang-ho’s 2016 Train to Busan (still an underappreciated genre high watermark), the fleet, ferocious, supernatural show—directed by Kim Seong-hun (Tunnel) and written by Kim Eun-hee (Signal), based on the latter’s popular webcomic series—is a superior breed of storytelling hybrid, with its political thrills expertly intertwined with apocalyptic mayhem. Though its characters may not fully resonate beyond their stock construction, it takes full advantage of its period-piece setting to create a raft of inventive set pieces, highlighted by an extended mid-season stretch of bedlam that alone marks it as a cut-above—and certainly superior to the likes of AMC’s stilted The Walking Dead.

Kingdom’s monstrous plague is accidentally brought about by Lord Cho, who, in an effort to keep the king alive—at least until the queen can pop out her baby boy—has a physician inject the ruler with a concoction made from a “resurrection plant” found in a foggy “Frozen Valley.” This is as unwise as it sounds, and leads to outright calamity when the doctor’s assistant is eaten by the king and his body is transported back to the village of Jiyulheon, where it’s then put in a stew by shady warrior Yeong-sin, who figures it’s preferable for the provincials to eat something than to die of hunger. Local nurse Seo-bi (Sense8’s Bae Doona) naturally objects to Yeong-sin turning her fellow citizens into unwitting cannibals… and that’s before their consumption of zombie-tainted meat transforms them all into the undead. Thus an unholy epidemic is born, putting everyone in dire peril (at least, during the night, since daylight sends these zombies scurrying under floorboards and boulders to hide from the glaring sun).

The quasi-vampiric nature of Kingdom’s creatures is a novel twist, but otherwise, the show adheres to canonical rules regarding their impulses (they want to chomp on anything living) and their eradication (aim for the head!). After a solid opening two episodes, the series kicks into gangbusters gear in its third installment, staging an eruption of gruesome anarchy in which the zombies, as fast as those found in Zack Snyder’s 2004 Dawn of the Dead remake, swarm through villages and forests, running down hills or streets like cascading insects or rodents, piling on top of each other to reach elevated targets, and tripping and falling over themselves in a thronged heap. No punches are pulled during these centerpieces; in one bracing instance, a young child watches as her mother devours her younger sister. As is always the case, containment turns out to be vital, and it’s predictably botched here, both by individuals who can’t believe such hellishness is real (until they see it with their own eyes) and, just as crucially, by arrogant government bigwigs more concerned with protecting noblemen than peasants.

Throughout, Crown Prince Lee is hunted by royal army adversaries operating under the false assumption that he’s betrayed the nation, and his attempt to survive this persecution (and regain his regal position) proves a reasonably sturdy narrative backbone. That Lee and Lord Cho aren’t exactly multifaceted protagonists is undeniable. Ju Ji-hoon and Ryu Seung-ryong, however, embody them with a vigorousness that never tips over into camp, and Kingdom fleshes out its material with a collection of colorful supporting characters whose purpose is to carry out grim heroic business (such as Yeong-sin, whose true identity is a running mystery) or supply comedy-relief levity (like a buffoonish if good-hearted magistrate with eyes for Seo-bi). Kim Eun-hee’s script glides smoothly between multiple points of interrelated interest, giving the proceedings an expansiveness that extends to its large-scale action sequences, which are embellished by horrific imagery, none better than the sight of zombies leaping upon unsuspecting men washing clothes in the moonlight.

Kingdom routinely exploits its ancient milieu for imaginative suspense. With limited weapons (mostly swords, spears and bows), vehicles (horse-drawn carts) and shelters (weakly fortified palaces located in the middle of nowhere), the Crown Prince and his allies find themselves unequipped to handle this pandemic, thereby upping the tension of each many-against-few siege. Moreover, the showrunners are resourceful in devising new ways to imagine the consequences of such an outbreak, as when Seo-bi seeks shelter from the rampaging hordes in a locked prison cell, and in the chamber next door, two imprisoned men shackled together by giant cangue (i.e. a wooden plank around their necks) wind up at each other’s throats when one of them is bitten by a zombie. “I’m exhausted!” the uninfected man amusingly screams as he tries to evade his clawing compatriot.

Kingdom’s twists can be easy to predict, but its propulsive energy is invigorating. Furthermore, as its zombie plague spreads across the nation, Lord Cho (and those like him) makes decisions that have terrible ramifications for society’s less fortunate—thus allowing the show to touch upon underlying class-warfare issues. Everyone craves something in this sterling import, be it power, justice, vengeance or the meat of a still-breathing human. By the conclusion of its cliffhanger finale, it’s likely audiences will be hungry too—for its already-greenlit second season.