There comes a point in “The Handmaiden,” a tantalizing triple-decker entertainment from South Korean director Park Chan-wook, when a book of lurid Japanese erotica opens up to reveal a drawing of an octopus wrapping its tentacles around a woman's nude body.

Consider this your trigger warning in light of recent election-season headlines, though Asian cinema aficionados will rightly interpret this image, plus a later shot of a giant octopus in a tank, as sly references to Park's most famous movie, “Oldboy” (2004), in which actor Choi Min-sik gobbled down a live cephalopod on camera. That scene was a nutty, showboating gesture in a movie with an abundance of outre gore and flashy style.

“The Handmaiden” is an unexpected delight. Without sacrificing his taste for psychosexual perversity or his flair for violent grace notes, Park has given us a teasingly witty and elegant puzzle box of a thriller whose pleasures are rooted not in visceral shock but in narrative surprise, and which wisely opts to seduce rather than pulverize its audience.

The result is the director's most absorbing feature in years and perhaps his finest since “Joint Security Area” (2000), a tense, human-scaled action movie that plays out within the moral minefield of Korea's Demilitarized Zone. Set during the 1930s, two decades before the historic demarcation of North and South, “The Handmaiden” straddles no less contested territory, specifically the politically fraught, linguistically complicated arena of Japanese-occupied Korea.

Park and Chung Seo-kyung's screenplay unfurls in three distinct chapters, the first of which follows a wily young pickpocket, Nam Sookee (Kim Tae-ri), who becomes the personal handmaiden of a beautiful Japanese heiress named Hideko (Kim Min-hee). In fact, Sookee is merely serving as the instrument of her boss (Ha Jung-woo), a smugly dashing con artist who, posing as a Japanese count named Fujiwara, has sinister designs on Hideko and her fortune.

And so Sookee and the count soon find themselves on the grounds of the magnificent estate where Hideko lives with her intensely domineering Korean uncle, Kouzuki (Cho Jin-woong). And despite the lush trappings of aristocratic privilege, the viewer almost immediately comes to share Sookee's sympathetic view of Hideko, a childlike, emotionally fragile creature who is forever being subjugated to the whims of men.

Park is an exquisite sensualist. He invites us to revel in every meticulous inch of Ryu Seong-hee's production design and to savor the coiffure and milk-white skin of his leading ladies as their emotional intimacy begins to breed sexual desire.

And he makes full, uninhibited use of the smoldering chemistry between the South Korean star Kim Min-hee (recently seen in Hong Sang-soo's excellent “Right Now, Wrong Then”) and Kim Tae-ri, a model making a fine screen-acting debut. The carnal, conspiratorial thrill of their scenes together is somehow inextricable from the thrill of watching them fight their way out of their circumstances.

The most intricately plotted movie about the art of the con in recent memory, “The Handmaiden” gradually reveals itself as a drama of physical, sexual and national freedom. It's a film whose idea of liberation begins with the suggestive licking of a lollipop but quickly advances into a triumphant expression of independence.