Detective Kien: The Headless Horror

Detective Kien: The Headless Horror (Vietnamese: Thám Tử Kiên: Kỳ Án Không Đầu) is a 2025 period horror-thriller film directed by Victor Vu. It is a spinoff of Vu's previous film, The Last Wife (2023), which featured the character of Detective Kien in a minor role;^[2] both films are adaptations of Hong Thai's novel The Lake of Vengeance.

The film was released in Vietnam on 30 April 2025.

During the Nguyễn dynasty in 19th-century Vietnam, in a remote Vietnamese village, a headless corpse was discovered. From that moment on, more decapitated bodies began appearing in the lake near the village—eight in total. The villagers believed these victims were slain by a supernatural guardian they called the "water wraith." Five years later, a woman named Moon is distraught when her niece, Nga, vanishes without a trace. While the villagers insist that Nga is taken by the water wraith, Moon refuses to believe it. Determined to uncover the truth, she seek help from Detective Kien, who years earlier arrest her corrupt husband.

Kien arrive and begin investigating Nga’s disappearance. His first stop is Nga’s home, where he learn that a thief break into her room the night she go missing, shattering a ceramic plate. At the lake, Kien meet a villager who find Nga’s shoe. Inside it, he discover seeds from the xanthium plant. Later, when visiting the village shaman, Kien is told that xanthium that xanthium grow near the waterfall close to the village.

Kien go to the waterfall with Moon and find traces of blood. Moon then share her past: Nga’s biological mother—Moon’s sister—had abandoned her when she was just a baby. Moon loved Nga deeply, so much so that Nga grew up seeing Moon as her true mother. However, Nga’s father, Vinh, dislike their closeness and forced Moon to leave. Without saying goodbye, Moon disappeared, leaving Nga to wait for her return for many years. When Nga eventually grew up, Moon came back. Although Nga was hurt by the abandonment, she chose to forgive Moon and welcome her back into her life.

Back in the village, Kien see a vision of Nga taken by the water wraith, her head severed. Kien then visit the district chief’s house to question his daughter, Tuyet, who is the last person to interact with Nga before she disappear. There, Kien also find a connection between the broken ceramic plate and Thac, Tuyet’s fiancé.

Kien visit Thac’s house and learn that Thac and Nga fall in love and have a relationship, but Thac cannot marry her because he is already engaged to Tuyet. During a family meeting between Thac and Tuyet’s families, Thac propose to make Nga his second wife, but Tuyet’s family reject the idea immediately. Later, when Kien return to Tuyet and Thac’s house, he find that Tuyet’s family accuse Nga of being pregnant, an accusation Thac deny.

Kien then have an idea to catch the thief who steal Nga’s ceramic plate. Moon hold a knife‑throwing contest to lure him out. After identifying him as a man named Dong, Kien and Moon go to his house and arrest him. When interrogated, Dong accuse Vinh of having an affair with the District Chief’s wife, Vuong. Kien immediately interrogate Vinh, and Vinh admit that he make a deal with Vuong to separate Thac and Nga in exchange for money to pay off his debts. After this investigation, Kien arrest Tuyet, suspected of harming Nga. Tuyet admit that she accidentally hit Nga’s head near the waterfall. After the arrest, Kien keep seeing visions of the water wraith. Meanwhile, Vuong order her servant Mui to ensure that Dong kill Nga. In a flashback, it reveal that a week earlier, when Tuyet hit Nga’s head at the waterfall, Mui followed her and found Nga unconscious. Mui informed Dong, who then took Nga’s body and imprisoned her in his secret cave, using her to blackmail Vuong. Not long after, a woman’s corpse believed to be Nga was found near the lake. Unable to bear his guilt, Vinh hanged himself, while Kien decided to exhume all eight victims of the water wraith buried in the village. After performing autopsies, Kien confirmed with certainty that the woman’s body found was not killed by the water wraith—and was not Nga.

Vuong, who want Nga killed quickly, take Mui to Dong’s house and ask him to kill Nga in exchange for money. Dong immediately kill Mui, believing she betray him, and drag Vuong to his place. Feeling threatened, Vuong say that he hide the payment money for Dong somewhere. He ask Dong to kill Nga in return for that reward. As Dong move to take the money, Nga see an opportunity and escape into the forest. Dong chase her, but Kien block his way. A fight break out between them, and Kien win, killing Dong. Meanwhile, Nga run with Moon, manage to knock Vuong unconscious, and tie her up.

Nga, Moon, and Kien return to the village, where Thac greet them and embrace Nga. As Detective Kien prepare to leave and say farewell, he realize the mystery of the water wraith that haunt the village for years. Kien reveal a plant used by the village shaman to cause frequent nosebleeds and hallucinations among the villagers, making them see apparitions of the water wraith. When Kien lead his men to arrest the shaman, he discover the severed head of the District Chief in the shaman’s house. Guided by a feather from the shaman’s winter cloak, Kien and his men pursue him north.

• Quoc Huy as Detective Kien
• Dinh Ngoc Diep as Miss Moon
• Tran Quoc Anh as Thac, a ceramic maker, Tuyet's fiancé
• Doan Minh Anh as Nga, Miss Mon's nephew, Vinh's son
• Pham Quynh Anh as Tuyet, Thac's fiancee
• My Uyen as Mrs. Vuong, Tuyet's mother, wife of the District Chief
• Sy Toàn as Dong, a thief who used to work for the District Head
• Xuân Trang as District Head
• Quốc Cường as village shaman
• Tín Nguyễn as Mui, a maid who works for the District Chief's family

Detective Kien was filmed in Vietnam's mountainous Northern Uplands region.^[3] Filming took place in Khuổi Ky, an ancient village with buildings made of stone; Khuổi Nhi Waterfall, in Na Hang district; and Vinh Quý Grass Hill.^[4][5] Due to the remoteness of the area, the crew had to dig their own roads and build bridges so vehicles carrying filming equipment could reach the locations, while some places could only be reached by boat. One small island where the fishing village scenes were filmed had no electricity, so cables were floated along the surface of the water to provide power.^[5]

There were 150 crew members on the shoot, along with 50-70 part-time crew and extras.^[5] The production attempted to depict historical Vietnamese society as faithfully as possible, recreating the appearance of a 200-year-old village.^[3][6] The crew designed close to 1,000 costumes appropriate for the Nguyễn dynasty era, with actors wearing three to five layers of clothing depending on their social hierarchy.^[7]

Detective Kien was released in Vietnam on 30 April 2025, timed to coincide with Reunification Day, the public holiday commemorating the end of the Vietnam War.^[7] It was released in theaters in the United States, Germany, Czech Republic and Slovakia on 29 May 2025, and in the UK, Canada, Norway, Sweden and Poland on 30 May 2025.^[6]

In the first week after its release, Detective Kien earned ₫143 billion (US$5.44 million) through 538,747 tickets sold in Vietnam.^[8] It ultimately made US$9.53 million in Vietnam and US$9.77 million worldwide, becoming the second-highest-grossing film of 2025 in Vietnam, and the eighth-highest-grossing film of all time in Vietnam.^[1][6]

Peter Martin of ScreenAnarchy gave the film a positive review, writing, "Detective Kien: The Headless Horror is an absorbing mystery that sometimes gets bloody and even occasionally gut-wrenching, yet avoids shock kills and clever cuts that are the stock in trade for modern Hollywood horror movies. The horror here comes from the evil that men — and sometimes women — are capable of inflicting upon other."^[9]

• Detective Kien: The Headless Horror at IMDb